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The marijuana detection window: Determining the length of time cannabinoids will remain detectable in urine following smoking. A critical review of relevant research and cannabinoid detection guidance for drug courts



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The duration of the urinary cannabinoid detection window is not settled
science. The number of days, following the cessation of marijuana
smoking, necessary for cannabinoids to become non-detectable using
traditional drug testing methods is the subject of debate among forensic
toxicologists and a matter of on-going scientific research. This article
makes no pretense to limit this important discussion, but rather, seeks
to enhance it. It is hoped that drug court practitioners will find that this
information clarifies some of the complex issues associated with the
elimination of marijuana from the human body.
Conventional wisdom has led to the common assumption that cannabinoids
will remain detectable in urine for 30 days or longer following the use
of marijuana. These prolonged cannabinoid elimination projections have
likely resulted in the delay of therapeutic intervention, thwarted the
timely use of judicial sanctioning, and fostered the denial of marijuana
usage by drug court participants.
This review challenges some of the research upon which the 30-plus day
elimination assumption is based. Careful scrutiny of these studies should
not be interpreted as an effort to discredit the findings or the authors
of this research. However, as our knowledge evolves, the relevancy of
previously published scientific data should be evaluated anew. One fact
is clear—more research is needed in the area cannabinoid elimination.
By Paul L. Cary, M.S.
Merely attempting to formulate cannabinoid
detection guidance invites controversy. Some
will argue that the proposed detection window
defined in this article is too short. Others will
suggest the opposite. Still others will insist
that the scientific evidence is insufficient to
allow the establishment of such guidance.
To some degree, each position has merit. No
detection window guidance, regardless of the
extent of scientific support, will encompass
every set of circumstances or all client situations.
If nothing else, the research demonstrates that
there is significant variability between individuals
in the time required to eliminate drugs.
These facts, however, should not preclude
the development of reasonable and pragmatic
guidance, supported by scientific research, for
use in the majority of drug court adjudications.
It is widely accepted that in order to instill
successful behavioral changes in a substance
abusing population, that consequences need
to be applied soon after the identification of
renewed or continued drug use. In a drug court
context, the application of judicial sanctions
and the initiation of therapeutic interventions
have been needlessly delayed due to a lack
of coherent guidance regarding the length of
time cannabinoids will likely remain detectable
in urine following the cessation of marijuana
smoking. The purpose of this article is to
provide that much needed guidance.
In a recent forensic publication, Dr. Marilyn
Huestis wrote: “Monitoring acute cannabis
usage with a commercial cannabinoid
immunoassay with a 50-ng/mL cutoff concen-
tration provides only a narrow window of
detection of 1–2 days,” (2002). In a 1985
article by Ellis et. al., researchers concluded;
“that under very strictly supervised absti-
nence, chronic users can have positive results
for cannabinoids in urine at 20 ng/mL or
above on the EMIT-d.a.u. assay 1for as many
as 46 consecutive days from admission, and
can take as many as 77 days to drop below
the cutoff calibrator for ten consecutive days.”
Based upon these seemingly divergent findings,
it is not difficult to comprehend why judges,
attorneys and other drug court professionals
are in a quandary regarding the length of time
marijuana can remain detectable in urine
following use. The dilemma—if the scientific
research seems not to be able to achieve
consensus on the urinary cannabinoid detection
window, how are those responsible for court
mandated drug supervision programs suppose
to understand and resolve this issue?
Like many other scientific and technical topics
that have been thrust into the judicial environ-
ment, the detection window of marijuana
is both complex and controversial, yet the
understanding of the pharmacology of this
popular substance is crucial to the adjudication
of cases in which marijuana usage is involved.
While the difficulties associated with estab-
lishing the length of time a drug will continue
to test positive in urine after use are not unique
to marijuana, the problem is exacerbated by
the extended elimination characteristics of
cannabinoids relative to other drugs of abuse,
most notably after chronic use.
The questions posed by drug court professionals
related to cannabinoid detection in urine include:
How many days is it likely to take for a chronic
marijuana user to reach a negative urine drug
test result?
How long can cannabinoids be excreted and
detected in urine after a single exposure to
How many days of positive urine drug
tests for cannabinoids constitutes continued
marijuana usage?
How often should a client’s urine be tested
to monitor for continued abstinence from
How many days should the court wait before
retesting a client after a positive urine drug
test for cannabinoids has been obtained?
How should the court interpret a positive
urine drug test for cannabinoids after a client
has completed an initial 30-day detoxification
period designed to “clean out” their system?
To one degree or another, answering these
questions depends upon the ability of the court
to estimate the length of time cannabinoids
will likely remain detectable in urine following
the use of marijuana by a drug court client.
Thus, the cannabinoid detection window
becomes a determinative factor in the appro-
priate interpretation of urine drug testing
results for marijuana. The lack of adequate
guidance has hindered the development of
these standards for use in drug court.
It is important to note that while courts
may be seeking absolute answers (an exact
cannabinoid detection window), the science
of drug detection in urine can only provide
reasonable best estimates. The law is not
always black and white; neither is science.
Therefore, precise “yes/no” answers or
exact detection windows are generally not
attainable. Sensible guidance for the interpre-
tation of urine cannabinoid results by drug
courts, however, is achievable.
Simply put, the detection window is the length
of time in days following the last substance
usage that sequentially collected urine samples
will continue to produce positive drug test
results—in other words, the number of days
until last positive sample. This time period is
not the same as the length of time a drug will
remain in someone’s system—that concept
is, in reality, indeterminable (given that there
is no analytical method capable of detecting
the presence of a single molecule of drug in a
donor’s body). The question being addressed
herein is not how long minute traces of mari-
juana will remain in a client’s tissues or fluids
after smoking, but rather how long those
residual cannabinoid metabolites will continue
to be excreted in urine in sufficient quantities
to produce a positive drug test (by standard
screening and confirmation testing).
For those compounds with uncomplicated
metabolic pathways or for those drugs that
are not significantly retained in body storage
compartments, detection times have been
established and generally accepted. These
include urinary detection windows for drugs
such as cocaine (1-3 days), amphetamines
and opiates (1-4 days), and PCP (1-6 days)
(Baselt, 2004). For marijuana, the urine elimi-
nation profile used to establish the detection
window is more complex. It is well docu-
mented and understood that cannabinoids are
lipid-soluble compounds that preferentially
bind to fat-containing structures within the
human body (Baselt, 2004). This and other
chemical characteristics can prolong the elimi-
nation half-life of cannabinoids and extend the
detection window beyond that of other abused
substances. Chronic marijuana use, which
expands body stores of drug metabolites
faster than they can be eliminated, further
increases cannabinoid detection time in urine.
Estimating the detection time of a drug in urine
is a complex task because of the many factors
that influence a compound’s elimination from
the body. Additionally, technical aspects of the
testing methods themselves also affect how
long a drug will continue to be detected in urine.
The pharmacological variables affecting the
duration of detection include drug dose, route
of administration, duration of use (acute or
chronic), and rate of metabolism. Detection
time is also dependent upon analytical factors
including the sensitivity of the test (cutoff
concentration) and the method’s specificity
(the actual drug and/or metabolite that is
being detected).
Study subjects with exceptionally long
cannabinoid detection times (30-plus
days) were just that-exceptional.
Generally speaking, the following factors
affect the marijuana detection window
Drug Dose
The higher the dose; the longer the detection
window. The percentage of psychologically
active delta-9 THC in marijuana plant material
varies considerably, making dosage difficult
to estimate.
Route of Entry
Inhalation (smoking) is the only route of
administration to be evaluated in this review.
Duration/Frequency of Use
The longer the duration and the greater the
frequency of cannabinoid usage (chronic);
the greater the body storage of fat-soluble
metabolites; the longer the cannabinoid
detection window. Drug surveillance pro-
grams may be able to define use patterns
based on client self-reporting, arrest reports,
documentation of previous treatment, or
other court records.
Metabolism Rate
The higher the metabolic functions of the client;
the faster cannabinoids are broken down;
the shorter the detection window. Monitoring
programs cannot determine this parameter.
Test Sensitivity
The lower the cutoff concentration; the more
sensitivity the testing method toward cannabi-
noids; the longer the detection window. Court
staff can select between various cannabinoid
testing cutoffs.
Test Specificity
The less specific the testing method; the
greater number of cannabinoid metabolites
detected; the longer the detection window.
This is difficult for monitoring programs to
assess without technical assistance.
Of these variables, drug courts are effectively
limited to controlling only the sensitivity of
the drug test itself (i.e., cutoff concentration).
Initial screening test cutoffs for cannabinoids
in urine generally include thresholds at 20, 50,
and 100 ng/mL. The choice of testing cutoff
has a profound effect on the cannabinoid
detection window. The only other factor that
can assist the court in the interpretation of
cannabinoid testing results and the estimation
of a client’s detection window is attempting
to define the duration and extent of a client’s
marijuana use over time (acute or chronic).
The differentiation between acute (a single
use event or occasional use) versus chronic
(persistent, long-term, continued usage) is
important to establishing reliable detection
benchmarks. As a result, drug court practitioners
should attempt to gather as much information
as they can about client drug use behavior
and patterns.
Finally, the detection window by its very
nature is subject to the timing of events
outside the purview of the court. The last use
of marijuana by a client prior to a positive test
is often unknown to drug court staff. Thus,
the real interval between drug usage and
first detection can rarely be ascertained.
For example, if a client smoked marijuana on
Monday and a urine sample collected on
Friday produced a positive result, the window
of detection is 4 days shorter than if that same
client had smoked on Thursday and produced a
positive cannabinoid test on Friday. Therefore,
the actual detection window for marijuana will
almost always be longer than the analytically
derived detection window as determined via
positive tests.
Research associated with the detection window
of cannabinoids in urine spans several decades.
While these studies have produced a signifi-
cant amount of valuable information about
marijuana elimination, older studies (primarily
those performed in the 1980’s) have also
yielded some unintended consequences as
pertains to the detection window. The tech-
nologies of drug testing and the methodologies
used in drug detection have advanced rapidly
in recent years. Consequently, cannabinoid
detection studies performed twenty years
ago (employing older immunoassays methods)
utilized drug testing methods that are either
no longer in widespread use or assays that
have been extensively reformulated.
As cannabinoid screening tests evolved, these
improved assays became more selective in
the manner in which they detected marijuana
metabolites (breakdown products). As detection
Table 1. Review of Cannabinoid Studies Reporting Long Detection Times
Detection Times
Determined for
Factors Potentially Affecting the Relevance
of Study Findings to Cannabinoid Detection
Window Interpretation
Year Author
36 days Retrospective case study of a single patient; report
on 6 similar cases included; no testing data provided
in publication; no cannabinoid cutoff given
1982 Dackis
et al.
37 days 27 subjects studied, no testing data provided in publication;
cannabinoid cutoff not provided; “calculated” cannabinoid
cutoff less than 10 ng/mL; 37 day detection derived from
95% confidence interval for calculated elimination half-life;
actual length of positivity averaged 9.7 days (5-20 days);
authors acknowledge subjects may have been able to
obtain marijuana during study; possibility supported by
staff monitoring subjects
1983 Cridland
et al.
40 days 10 subjects studied; self-reported as chronic users; subjects
housed on unrestricted drug treatment ward; marijuana
use during study suspected by authors and confirmed by
several subjects
1984 Swatek
67 days 86 subjects studied; self-reported as chronic users; subjects
treated on “closely supervised” ward; single case of an
individual’s time to last positive urine (at or above 20 ng/
mL) of 67 days (77 days to drop below the cutoff calibra-
tor for ten consecutive days); spikes in urine cannabinoid
levels during the study are not explained by the authors
1985 Ellis et al.
25 days 11 subjects studied for cannabinoid elimination patterns
(70 participants in entire study); only one subject
remained positive for 25 days; mean elimination for
self-reported “heavy” users was 13 days; immunoassay
used in study not commercially available since 1995.
1985 Schwartz
et al.
25 days 13 subjects studied; self-reported as chronic users; subject
abstinence not supervised during study; subjects allowed
to smoke marijuana before and on the day of test drug
administration; only one subject tested positive beyond
14 days
1989 Johansson
& Halldin
25 days Subject detection times determined using methods with
a 5 ng/mL cannabinoid cutoff concentration
1994 Iten
32 days 19 subjects studied - half withdrew from study prior to
completion; subjects were prisoners housed in general
population with no additional surveillance; participants
not asked to report new drug use during study; marijuana
use during study suspected by authors
1999 Smith-
et al.
specificity increased, the length of time
cannabinoids were being detected in urine
decreased. The greater the cannabinoid testing
specificity, the shorter the detection window.
Studies have demonstrated that detection
times of cannabinoid metabolites in urine
monitored by immunoassay have decreased
over the past two decades (Huestis, 2002;
Huestis, Mitchell, & Cone, 1994). Therefore,
the results of cannabinoid elimination
investigations performed in the 1980’s may
no longer be applicable to estimating the
detection window for marijuana in urine using
today’s testing methodologies. Not to men-
tion that twenty years ago, the routine use of
on-site drug testing devices was nonexistent.
Studies of chronic marijuana users reporting
prolonged cannabinoid excretion profiles have
provided the basis for the common assump-
tion that marijuana can be detected in urine
for weeks or even months following use. In
general, cannabinoid elimination studies that
have manifested exceptionally long detection
times suffer from a variety of research design
shortcomings that raise concerns about their
usefulness in establishing a reliable cannabi-
noid detection window for use in the modern
drug court movement. Table I examines
some of the potentially limiting factors from
studies that produced prolonged cannabinoid
detection times.
The research studies presented in Table 1
contain numerous design details that confound
the use of the data presented in establishing
a reasonable and pragmatic cannabinoid
detection window for drug court proceedings.
The most serious of these obfuscating factors
is the inability to assure marijuana abstinence
of the subjects during the studies. The adverse
effect of this flaw on determining the true
cannabinoid elimination time after marijuana
cessation is significant. Drug use during an
elimination study would extend the duration
cannabinoids would be detected in the urine
of subjects and would produce inaccurately
long detection windows. In several cases, the
authors themselves in their own review of
results raise this concern. Other study design
issues that may limit their usefulness include
the use of detection methods with cannabinoid
cutoff concentrations far below those tradi-
tionally utilized in criminal justice programs, the
use of testing methods no longer commercially
available and the use of immunoassay drug
tests with reduced cannabinoid specificity (as
compared with current immunoassay testing
methods). It is not the intention of this article
to discredit these studies, but rather to illus-
trate the degree to which their prolonged
cannabinoid detection findings have influenced
the understanding of the length of time
cannabinoids can be detected in urine.
This critical evaluation (Table 1) is not present-
ed to imply that these peer-reviewed articles
are unscientific or contain no information of
probative value. It is insufficient, however, to
merely read the abstract of a scientific paper
or the findings of a research study and draw
the conclusion that a drug court client can
remain positive for 30 days or longer, based
upon the longest cannabinoid detection time
reported therein. The data from these studies
are often misused to make such claims.
Despite the potential limitations affecting the
interpretation of the data produced by the
studies in Table 1, the research does present
some general cannabinoid elimination trends
worth further examination. A closer evaluation
of the study by Smith-Kielland, Skuterud, &
Morland indicates that even with the factors
identified as limiting its relevance, the aver-
age time to the first negative urine sample at
a cannabinoid cutoff of 20 ng/mL was just 3.8
days for infrequent users and only 11.3 days
for frequent users (1999). In the Swatek study,
eight out of ten chronic subjects tested below
the 50 ng/mL cutoff after an average of only
The detection window for cannabinoids
in urine must be seen in the proper
context-as a reasonable estimate.
13 days (range 5-19 days) (1984). Johansson
and Halldin identified only one study subject
that tested positive for longer than 14 days
with all thirteen subjects having an average
last day with detectable levels (using a 20
ng/mL cutoff) of 9.8 days (1989). In other
words, despite the potential factors restricting
interpretation, those study subjects with
exceptionally long cannabinoid detection times
(30-plus days) were just that—exceptional.
In several of the studies presented in Table 1,
only a single subject was the source of the
maximum cannabinoid detection time.
Unfortunately, these rare occurrences have
had a disproportional influence on the overall
cannabinoid detection window discussion in
a manner that has led to the general assump-
tion that 30-plus day detection times are
routine in drug court clients—regardless of
use patterns (chronic vs. acute). Moreover,
this prolonged elimination assumption and
its widespread use as exculpatory evidence
has most likely fostered client denial and
hindered legitimate sanctioning efforts.
By contrast, the research associated with acute
marijuana usage and resulting cannabinoid
detection window is considerably more
straightforward and less contentious. In a 1995
study using six healthy males (under continu-
ous medical supervision), Huestis, Mitchell,
& Cone determined that the mean detection
times following a low dose marijuana cigarette
ranged from 1 to 5 days and after a high dose
cigarette from 3 to 6 days at a 20 ng/mL
immunoassay cutoff concentration (average
2.1 days and 3.8 days, respectively) (1995).
They also concluded that immunoassays at
the 50 ng/mL cannabinoid cutoff provide only
a narrow window of detection of 1-2 days
following single-event use. In 1996, Huestis
et. al. published research focusing on carboxy-
THC, the cannabinoid metabolite most often
identified by gas chromatography/mass
spectrometry (GC/MS) confirmation methods.
Using the 15 ng/mL GC/MS cutoff, the detec-
tion time for the last positive urine sample
(for six subjects following high dose smoking)
was 122 hours—just over five days. In 2001,
Niedbala et. al. demonstrated similar results
with 18 healthy male subjects following the
smoking of cigarettes containing an average
THC content of 20-25 mg. Analyzing urine
samples at a 50 ng/mL immunoassay cutoff
yielded an average cannabinoid detection
time of 42 hours. These acute marijuana
elimination studies conclude that after single
usage events cannabinoids are detected in
urine for no more than a few days.
While studies of the cannabinoid detection
window in chronic substance users have
been more difficult to accomplish, research
protocols have been developed to overcome
concerns about marijuana usage during the
study. Using a well-crafted study design,
Kouri, Pope, & Lukas in 1999 determined the
cannabinoid elimination profiles of 17 chronic
users. Subjects were selected after reporting
a history of at least 5000 separate “episodes”
of marijuana use in their lifetime (the equiva-
lent of smoking once per day for 13.7 years)
plus continuing daily usage. Abstinence during
the 28-day study was ensured by withdrawing
those subjects whose normalized urine
cannabinoid levels (cannabinoid/creatinine
ratio) indicated evidence of new marijuana use.
Kouri, et al, found that five of the 17 subjects
reached non-detectable levels (less than 20
ng/mL) within the first week of abstinence,
four during the second week, two during the
third week and the remaining six subjects
still had detectable cannabinoid urinary levels
at the end of the 28-day abstinence period.
Unfortunately, analytical results related to the
cannabinoid testing in the article were scant
as the primary objective of the study was to
assess changes in aggressive behavior during
withdrawal from long-term marijuana use.
Even though this represents one of the best
studies of chronic marijuana users, interpreta-
tion of this data for cannabinoid elimination
purposes is limited because the actual drug
testing data is not available. Nonetheless,
Kouri, et al, shows that after at least 5000
marijuana smoking episodes, 30-day elimination
times are possible.
A 2001 research project by Reiter et al. also
seemed to avoid many of the design issues
cited as concerns in Table 1. Reiter’s case
study involved 52 volunteer chronic substance
abusers drug tested on a detoxification ward.
Daily urine and blood tests excluded illicit
drug consumption during the study. Using a
20 ng/mL immunoassay cutoff, the maximum
elimination time (last time urine tested above
the cutoff) for cannabinoids in urine was
433.5 hours (or just over 18 days); with a
mean elimination time of 117.5 hours (4.9
days). When controlling for covert marijuana
use by subjects during the study, chronic
users in this study did not exhibit detectable
urine cannabinoid levels for even three weeks.
In aggregate, using the data from the five
studies cited in this review that researchers
described as chronic marijuana users (even
including data from Table 1), the average
detection window for cannabinoids in urine at
the lowest cutoff concentration of 20 ng/mL
was just 14 days (Ellis, et al, 2002; Iten, 1994;
Niedbala, 2001; Schwartz, Hayden, & Riddile,
1985; Swatek, 1984).
The assumption that cannabinoids can be rou-
tinely detected in urine following the smoking
of marijuana for 30 days or longer appears
widespread and longstanding. Exacerbating
this problem is the nearly constant proliferation
of published material that continually reinforces
the 30-plus day cannabinoid detection window
into the criminal justice psyche. Examples of
the enormous body of information/literature
that propagates the 30-plus day cannabinoid
detection times abound:
Substance abuse treatment literature pro-
claiming that “some parts of the body still
retain THC even after a couple of months.”2
Drug abuse information targeted toward teens
that often presents unrealistic cannabinoid
detection times such as; “Traces of THC can
be detected by standard urine and blood tests
for about 2 days up to 11 weeks.”3
Criminal justice publications that list the
cannabinoid detection limits of a “Chronic
Heavy Smoker” as “21-27 days.”4
Drug testing manufacturers’ pamphlets
that state the time to last cannabinoid
positive urine sample as “Mean = 27.1 days;
Range = 3-77 days.”5
General information websites that offer
“expert” advice concluding, “The average
time pot stays in your system is 30 days.”6
Urine tampering promotions in magazines
such as High Times and on websites that
offer urine drug cleansing supplements and
adulterants intended to chemically mask the
presence of drugs in urine often exaggerate
the detection window in an effort to promote
the continued use of their products. Some of
their claims include: drug detection times in
urine [for] “Cannabinoids (THC, Marijuana)
20-90 days,”7and detection times for smokers
who use “5-6x per week—33-48 days.”8
Health information websites that provide the
following guidance; “At the confirmation level
of 15 ng/ml, the frequent user will be positive
for perhaps as long as 15 weeks.”9
Dr. Drew Pinsky (a.k.a. Dr. Drew), who has
co-hosted the popular call-in radio show
Loveline for 17 years, states that “Pot stays
in your body, stored in fat tissues, potentially
your whole life.”10
Based upon these information sources that
claim cannabinoids elimination profiles of 25
days, 11 weeks, 90 days, up to 15 weeks after
use, and for “your whole life,” is it any wonder
that drug court professionals cannot reach
consensus on this issue? Is there any doubt
why drug court clients make outlandish
cannabinoid elimination claims in court? These
represent but a sampling of the many dubious
sources that perpetuate the prolonged cannabi-
noid detection window. As a consequence,
the 30-plus day cannabinoid elimination period
remains a commonly assumed “fact.”
The detection window for cannabinoids in
urine must be seen in the proper context—
as a reasonable estimate. Detection times
for cannabinoids in urine following smoking
vary considerably between subjects even in
controlled smoking studies using standardized
dosing techniques. Research studies have also
demonstrated significant inter-subject differ-
ences in cannabinoid elimination rates. The
timing of marijuana elimination is further com-
plicated by the uncertainty of the termination of
use and continued abstinence. That said, gen-
eral estimates for establishing a cannabinoid
detection window in urine can be advanced
and accepted for use in drug courts. Based
upon the current state of cannabinoid elimina-
tion knowledge and the drug testing methods
available in today’s market, the following practical
cannabinoid detection guidance is offered.
Based upon recent scientific evidence, at
the 50 ng/mL cutoff concentration for the
detection of cannabinoids in urine (using
the currently available laboratory-based
screening methods) it would be unlikely for
a chronic user to produce a positive urine
drug test result for longer than 10 days after
the last smoking episode. Although there are
no scientific cannabinoid elimination studies
on chronic users using non-instrumented
testing devices, one would assume that if
the on-site devices are properly calibrated
at the 50 ng/mL cutoff level the detection
guidance would be the same.
At the 20 ng/mL cutoff concentration for the
detection of cannabinoids in urine (using
the currently available laboratory-based
screening methods) it would be uncommon
for a chronic marijuana smoker to produce
a positive urine drug test result longer than
21 days after the last smoking episode.
For occasional marijuana use (or single
event usage), at the 50 ng/mL cutoff level,
it would be unusual for the detection of
cannabinoids in urine to extend beyond
3-4 days following the smoking episode
(using the currently available laboratory-
based screening methods or the currently
available on-site THC detection devices).
At the 20 ng/mL cutoff for cannabinoids,
positive urine drug test results for the
single event marijuana use would not be
expected to be longer than 7 days.
This cannabinoid detection guidance should
be applicable in the majority of drug court
cases. These parameters (acute vs. chronic),
however, represent opposite ends of the
marijuana usage spectrum. Clients will often
exhibit marijuana-smoking patterns between
these two extremes resulting in an actual
detection window that lies within these limits.
As noted in the Kouri, et al, study, research
suggests that under extraordinary circum-
stances of sustained, extended and on-going
chronic marijuana abuse (thousands of
smoking episodes over multiple years)
that 30-day urinary cannabinoid detection is
possible in some individuals at the 20 ng/mL
cutoff (1999). However, the burden of proof
for documenting such aberrant and chronic
marijuana use patterns should fall on the drug
court client or the client’s representatives.
For a client to simply disclose “chronic” use is
insufficient corroboration.
Much has been made about marijuana research
that has produced dramatically prolonged
cannabinoid elimination times, particularly in
those subjects identified as chronic. This data
has often been used to explain continuing
positive cannabinoid test results in clients long
after their drug elimination threshold (resulting
in negative urine drug tests) should have been
reached. The pertinent question: to what
extent does the scientific data (demonstrating
30-plus day cannabinoid detection times in
chronic users) influence the disposition of
drug court cases? Put another way, do drug
court practitioners need to be concerned
about the potential of extended cannabinoid
detection times impacting court decisions
(i.e., sanctions)? In reality, the only timeframe
in which an individual’s chronic marijuana use
(possibly leading to extended cannabinoid
elimination) is relevant is during a client’s
admission into the drug court program. It is
during this initial phase that the court may
find itself attempting to estimate the number
of days necessary for a client’s body to rid
itself of acquired cannabinoid stores and the
time required to produce negative drug test
results. In many programs, a detoxification
period is established for this purpose. Once in
the drug court program (following the initial
detoxification phase), the extent of a client’s
past chronic marijuana usage does not influence
the cannabinoid detection window as long as
appropriate supervision and drug monitoring
for abstinence continues on a regular basis.
It would seem reasonable to assume that
chronic client marijuana usage of the extreme
levels discussed here while within a properly
administered drug court would be highly
unlikely. Therefore, the consequences of
chronic marijuana usage on the cannabinoid
detection window are effectively limited to
the initial entry phase of the program.
The cannabinoid detection window guidance
provided herein relies upon the widely used
cutoff concentrations for the initial screening
tests—20 ng/mL and 50 ng/mL. For programs
utilizing GC/MS confirmation for the validation
of positive screening results, the confirmation
cutoff has little influence on the length of
the cannabinoid detection window in urine.
A review of the potential result possibilities
demonstrates this point. If a drug court sample
tests negative for cannabinoids on the initial
screen, the confirmation cutoff is obviously
irrelevant because the sample is not submitted
for confirmation testing. If a sample both
screens and confirms as positive for cannabi-
noids (and is reported as positive), then the
cutoff concentration of the confirmation
analysis is also not relevant because the sam-
ple would not have been sent for confirmation
unless it produced a result greater than or
equal to the cutoff level of the initial screening
test. In other words, the confirmation proce-
dure is merely validating the results (and
therefore the cutoff) of the original screening
test. The only scenario in which the confirma-
tion cutoff could potentially impact the length
of the cannabinoid detection window is if a
sample screened positive and the confirmation
procedure failed to confirm the presence of
cannabinoids (and the results of the drug test
were reported as negative). In this circum-
stance, the cannabinoid detection window
might be shorter than the estimate provided as
guidance. This would be true on the condition
that the confirmation cutoff concentration was
lower than that of the screening procedure—
which is nearly always the case. A shorter
cannabinoid detection window would not
be seen as prejudicial to the client and might
actually be beneficial to the drug court.
Using this cannabinoid detection window
guidance, the drug court decision-making
hierarchy should be able to establish reason-
able and pragmatic cannabinoid detection
benchmarks that both provide objective
criteria for court decisions and protect clients
from inappropriate or unsupportable conse-
quences. Some courts may choose to use the
cannabinoid elimination information detailed
in this paper exactly as presented to establish
a marijuana detection window that will allow
the differentiation between abstinence and
continued/renewed use. Other courts may
decide to build into the guidance an additional
safety margin, granting clients further benefit
of the doubt. Regardless of the approach,
however, courts are urged to establish detec-
tion benchmarks and utilize these scientifically
supportable criteria for case disposition.
Every day drug courts grapple with two seem-
ingly disparate imperatives—the need for rapid
therapeutic intervention (sanctioning designed
to produce behavioral change) and the need to
ensure that the evidentiary standards, crafted
to protect client rights, are maintained. While
administrative decision-making in a drug
court environment (or a probation revocation
hearing) does not necessitate the same due
process requirements and protections that
exist in criminal cases, as professionals we
are obliged to ensure that court decisions
have a strong evidentiary foundation.
Science is not black and white
and the state of our knowledge
is continually evolving.
Courts establishing detection windows for
cannabinoids need to be aware of the exis-
tence of research studies indicating prolonged
elimination times in urine. It is not recom-
mended, however, that drug courts manipulate
their detection windows to include these
exceptional findings. Sound judicial practice
requires that court decisions be based upon
case-specific information. In weighing the
evidence, courts also acknowledge the reality
that a particular client’s individualities or the
uniqueness of circumstances may not always
allow the strict application of cannabinoid
detection window parameters in a sentencing
decision. These uncommon events, however,
should not preclude the development of
cannabinoid detection windows for the use
in the majority of court determinations.
As a result of the extended elimination of
cannabinoids (as compared to other abused
drugs), some drug courts have instituted a
detoxification stage or “clean out” period in
the first phase of program participation. This
grace period allows new clients a defined
time frame for their bodies to eliminate stores
of drugs that may have built up over years
of substance abuse without the fear of court
sanctions associated with a positive drug
test. In many cases this detoxification period
extends for 30 days, which corresponds
to the commonly held assumption that
this represents the time period required for
marijuana metabolites to be eliminated from
a client’s system.
Regardless of the origin of the 30-day marijuana
detection window and its influence on the
duration of the detoxification period, 30 days
is certainly an equitable time period for client
drug elimination purposes. Simply because
the science may not support the necessity of
a detoxification period of this duration does
not mean that a court cannot use the 30-day
parameter in order to establish program
expectations. However, based upon the
cannabinoid detection guidelines presented in
this review, it is unlikely (utilizing reasonable
physiological or technology criteria) that a drug
court client would continue to remain cannabi-
noid positive at the end of this designated
abstinence period. After 30 days, using either
a 20 or 50 ng/mL testing cutoff, continued
cannabinoid positive urine drug tests almost
certainly indicate marijuana usage at some
point during the detoxification period and
should provoke a court response to reinforce
program expectations.
The abstinence baseline can either be a point
at which a client has demonstrated their
abstinence from drug use via sequentially
negative testing results (actual baseline) or
a court-established time limit after which a
client should not test positive if that client
has abstained from marijuana use (scientific
baseline). Each baseline has importance in
a court-mandated drug monitoring program.
The later has been the focus of this review.
It is exemplified by establishing the detection
window for marijuana and utilizing positive
urine drug testing results to guide court
intervention. Individuals who continue to
produce cannabinoid positive results beyond
the established detection window maximums
(the scientific baseline) are subject to sanction
for failing to remain abstinence during pro-
gram participation.
The alternative approach uses negative test
results in establishing the actual abstinence
baseline. This has been referred to as the
“two negative test approach” and has been
Courts are urged to establish
detection benchmarks and utilize
these scientifically supportable
criteria for case disposition.
previously described in the literature (Cary,
2002). A drug court participant is deemed to
have reached their abstinence baseline when
two consecutive urine drug tests yielding
negative results for cannabinoids have been
achieved, where the two tests are separated
by a several day interval. Any positive drug
test result following the establishment of this
baseline indicates new drug exposure. This
technique can be used with assays that test
for marijuana at either the 20 or 50 ng/mL
cutoff concentration.11
Due to the prolonged excretion profile of
cannabinoids in urine (especially after chronic
use) some drug court programs wrestle
with the issue of whether to continue urine
drug testing during the expected marijuana
elimination period. Simply put, why continue
the expense and sample collection burden
for clients who have already tested positive
for cannabinoids knowing that the client may
continue to produce positive cannabinoid
results for many days? There are at least
three principle reasons drug courts are not
advised to suspend urine drug testing following
a positive result for cannabinoids.
First, most court-mandated testing includes
drugs other than marijuana. Client surveillance
often encompasses testing for many of
the popularly abused substances such as
amphetamines, cocaine, opiates, and alcohol.
Programs that forego scheduled testing run
the very real risk of missing covert drug use
for substances other than marijuana. If a drug
court client knows a positive cannabinoid
test will result in a drug testing “vacation,”
they may use that non-testing period to use
substances with shorter detection windows
(i.e. cocaine or alcohol). By continuing to test,
the court maintains its abstinence monitoring
for drugs besides marijuana.
Second, from a programmatic standpoint the
suspension of scheduled client drug testing
sends the wrong therapeutic message. If a
drug court's policies and procedures require
a certain schedule of testing, suspending
testing for even a short period may appear
to other program participants that the court is
“rewarding” a client who has tested positive.
Eliminating scheduled drug tests in response
to a positive cannabinoid result degrades
the program’s efforts at maintaining client
behavioral expectations.
Lastly, depending upon the cutoff concentration
of the drug test being used and whether the
client’s marijuana usage was an isolated event
(rather than a full relapse), it is entirely possible
that a client who has previously tested positive
for cannabinoids may test negative sooner than
the cannabinoid detection window estimate.
As indicated earlier, acute marijuana use
results in cannabinoid positive urine samples
for only several days following exposure.
Curtailing drug testing for longer than three
days extends unnecessarily the period of
uncertainty about a client’s recent behavior and
may delay appropriate therapeutic strategies
or sanction decisions.
One of the most important prerogatives of
drug court (or any therapeutic court) is to
clearly define the behavioral expectations for
clients by establishing compliance boundaries
required for continued program participation.
Drug testing used as a surveillance tool defines
those boundaries and monitors client behavior
in order that the court can direct either incen-
tives or sanctions as needed to maintain
participant compliance. To fulfill this important
responsibility, drug courts teams must agree
upon specific drug testing benchmarks in
order to apply court intervention strategies
in an equitable and consistent manner.
The primary focus of this article is to promote
the establishment of a drug testing benchmark
that defines the expected detection window
of cannabinoids in urine following the cessa-
tion of smoking. In order for drug courts to
determine their cannabinoid detection window,
the program will need to consider the cutoff
concentration of the urine cannabinoid test
being utilized and develop criteria for defining
chronic marijuana users. Drug courts should
also take into account how the cannabinoid
detection window will be incorporated into
their current policies and procedures and how
the detection window will be used in case
adjudication. Once established, the court
should apprise program participants of the
expectations associated with the cannabinoid
detection window. Clients should understand
that sanctions will result if continued cannabi-
noid positive tests occur beyond the estab-
lished detection window (the drug elimination
time limit after which a client should not test
positive if that client has abstained from
marijuana use). Courts are reminded that the
cannabinoid detection window may require
revision if there are modifications to the drug
testing methods or if there are significant
changes in marijuana usage patterns in the
court’s target population (i.e., significant
increases in chronic use).
Practitioners are reminded that the goal in
establishing a cannabinoid detection window
is not to ensure that a monitored client is
drug free. Chronic marijuana users may carry
undetectable traces of drug in their bodies
for a significant time after the cessation of
use. Rather, the goal is to establish a given
time period (detection window limit) after
which a client should not test positive for
cannabinoids as a result of continued excretion
from prior usage.
Finally, the cannabinoid detection window is
a scientifically supportable, evidence-based
effort to establish a reasonable and practical
standard for determining the length of time
cannabinoids will remain detectable in urine
following the smoking of marijuana. Drug courts
are reminded that science is not black and
white and that the state of our knowledge is
continually evolving. While detection window
benchmarks will and should guide the sanc-
tioning process for violations of abstinent
behavior, courts are urged to judge a client’s
level of compliance on a case by case basis
using all of the behavioral data available to the
court in conjunction with drug testing results.
In unconventional situations that confound
the court, qualified toxicological assistance
should be sought.
Paul L. Cary, M.S. is the Director of the Toxicology
& Drug Monitoring Laboratory, University of Missouri
Health Care, Columbia, Missouri; and NDCI Faculty
Resident Expert on drug testing issues. Mr. Cary can
be reached at
This document was published with support from the
Office of National Drug Control Policy, Executive Office
of the President and the Bureau of Justice Assistance,
U.S. Department of Justice.
Baselt, R.C. (2004). In Disposition of Toxic Drugs
and Chemicals in Man, (7th ed.). Foster City,
CA: Biomedical Publications.
Cary, P.L. (2002). The use creatinine-normalized
cannabinoid results to determine continued
abstinence or to differentiate between new
marijuana use and continuing drug excretion
from previous exposure. Drug Court Review,
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Cridland, J.S., Rottanburg, D., & Robins, A.H. (1983).
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Ellis, G.M., Mann, M.A., Judson, B.A., Schramm,
N.T., & Tashchian, A. (1985). Excretion patterns
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excretion half-life of 1-tetrahydrocannabinol-7-
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Kouri, E. M., Pope, H. G. Jr., & Lukas, S. E. (1999).
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Niedbala, R.S., Kardos, K.W., Fritch, D.F., Kardos,
T.F., & Waga, J. (2001). Detection of marijuana
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Friedrich, H.J., & Ochmichen, M. (2001). Time
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1. EMIT is a registered trademark of the Dade
Behring/SYVA Company and stands for (Enzyme
Multiplied Immunoassay Technique). EMIT
is a commercial drug testing product for the
analysis of drugs of abuse in urine (d.a.u.).
2. Detoxing from Marijuana (pamphlet). (1992).
Marijuana Anonymous: 12-Step Program for
Marijuana Addicts, 4. The entire text reads as
follows: “Why do some effects last so long?”
“Unlike most other drugs, including alcohol,
THC (the active chemical in marijuana) is stored
in the fat cells and therefore takes longer to
fully clear the body than with any other common
drug. This means that some parts of the body
still retain THC even after a couple of months,
rather than just the couple of days or weeks for
water soluble drugs.”
3. Website: TeenHealthFX. URL: is a project funded by
Atlantic Health System, a New Jersey hospital
consortium. The website states that “the
professional staff who answer questions from
our vast audience and provide oversight include
clinical social workers, health educators,
adolescent medicine physicians, pediatricians
and pediatric subspecialists, psychiatrists,
psychologists, nurses, nutritionists, and many
other health professionals.”
QUESTION: “Dear TeenHealthFX,
Smoking marijuana can be detected how long?
I’ve heard a couple of weeks in urine, a couple
of days in blood, and a couple of years in hair…
please clarify! Also, during a routine physical at
the doctor, will they check for marijuana in the
blood or urine sample?
Signed: Longevity Of Marijuana - How Long
Does It Stay In Your System”
ANSWER: “Dear Longevity Of Marijuana - How
Long Does It Stay In Your System, The chemical
in marijuana, THC, is absorbed by fatty tissues in
various organs. Traces of THC can be detected
by standard urine and blood tests for about
2 days up to 11 weeks depending on the per-
son’s metabolism, how much they smoked and
how long they smoked. THC can be detected
for the life of the hair. Again, the sensitivity of
the test ranges from person to person depending
on many factors including the amount of body
fat, differences in metabolism, and how long
and how much they smoked.”
Presumably, the 11 week estimate comes from
the research finding of Ellis, et. al. (1985) which
has been described earlier.
4. Bureau of Justice Assistance Monograph entitled:
Integrating Drug Testing into a Pretrial Services
System: 1999 Update, July 1999, NCJ # 176340.
On page 48, Exhibit 5-3 titled; Approximate
Duration of Detectability of Selected Drugs in
Urine lists Cannabinoids (marijuana) Chronic
heavy use as 21 to 27 days. Source: Adapted
from the Journal of the American Medical
Association’s Council on Scientific Affairs (1987,
p. 3112).
The source material citation is the Journal of
the American Medical Association. (1987, June)
12;257(22):3110-4. The article is titled;
“Scientific Issues in Drug Testing—Council on
Scientific Affairs.” On page 3112, Table 2. titled
“Approximate Duration of Detectability of
Selected Drugs in Urine” lists chronic heavy
smoker as 21-27 days. The references cited for
this data are Dackis, et. al (1982), and Ellis, et.
al. (1985), the potential shortcomings of both
have been discussed in this article. It is note-
worthy and illustrative that this 1999 “updated”
publication still relies on research performed in
1982 and 1985.
5. Cannabinoid Issues: Passive Inhalation,
Excretion Patterns and Retention Times
(pamphlet). (1991). Dade Behring, SYVA
Company, S-10036. On page 25 in a table
titled: “Emit d.a.u. Cannabinoid Assay (20
ng/mL)” is listed the following:
All Subjects (n = 86):
First Negative:
Mean = 16.0 days Range = 3-46 days
Last Positive:
Mean = 27.1 days Range = 3-77 days
Examination of the references associated with
this data indicates the following sources; Ellis,
et. al. (1985), Schwartz, Hayden, & Riddile (1985),
and Johansson& Halldin (1989). All of these
references and their potential study design issues
have been reviewed in this article. This pam-
phlet also contains cannabinoid elimination data
using the Emit-st Cannabinoid Assay testing
method. Given that this assay is no longer
being manufactured, the data was not included.
6. Website: What You Need to Know.
This is a popular website for general information
inquiries about almost any subject matter. In a
section entitled “About Our Service” the web-
site states, “Allexperts, created in early 1998,
was the very first large-scale question and
answer service on the net! We have thousands
of volunteers, including top lawyers, doctors,
engineers, and scientists, waiting to answer
your questions. All answers are free and most
come within a day!”
The question submitted to the site was, “How
long does marijuana stay in your system?” The
expert response was: “The average time pot
stays in your system is 30 days. The time may
differ depending on your metabolism. If you
have a fast metabolism it may be shorter than
30 days, if you have a slow metabolism it may
be more. The average though is about 30 days.”
Note that in this answer, 30 days is given as an
average cannabinoid elimination time.
7. Website: Health Choice of New York. URL:
. This website states: “It's One Stop Shopping
For All Of Your Detoxifying Needs. We Have All
The Products You Need To Pass A Urine Drug
Test.” In a section entitled “Drug Approximate
Detection Time in Urine,” the site provides the
following information: “Cannabinoids (THC,
Marijuana) 20-90 days.”
8. Website: IPassedMyDrugTest.Com. URL:
The following table is provided:
Cannabinoids (THC, Marijuana) Detection Time:
1 time only 5-8 days
2-4x per month 11-18 days
2-4x per week 23-35 days
5-6x per week 33-48 days
Daily 49-63 days
9. Website: HealthWorld Online. URL:
Site’s mission statement; “HealthWorld Online
is your 24-hour health resource center—a virtual
health village where you can access informa-
tion, products, and services to help create your
wellness-based lifestyle.” In the section called
“Detection of Cannabinoids in Urine,” the fol-
lowing information is provided: “Cutoff and
Detection Post Dose: The initial screening cut-
off level is 50 ng/ml. The GC/MS cutoff level is
15 ng/ml. The elimination half-life of marijuana
ranges from 14-38 hours. At the initial cutoff of
50 ng/ml, the daily user will remain positive for
perhaps 7 to 30 days after cessation. At the
confirmation level of 15 ng/ml, the frequent
user will be positive for perhaps as long as 15
10.Website: Dr. Drew. URL:
QUESTION: How long does pot (or other drugs)
stay in your body? Is there any way to detect it?
ANSWER: Most readily available drug screens
are tests of the urine. Blood tests and breath
analyzers are another way substances can be
detected. Pot stays in your body, stored in fat
tissues, potentially your whole life. However,
it is very unusual to be released in sufficient
quantities to have an intoxicating effect or be
measurable in urine screens. Heavy pot smokers,
people who have smoked for years on a daily
basis, very commonly have detectable amounts
in their urine for at least two weeks.
4900 Seminary Road, Suite 320
Alexandria, VA 22311
(703) 575-9400
(703) 575-9402 Fax
11.Research data indicates that in the terminal
phase of cannabinoid elimination, subjects can
produce urine samples with levels below the
cutoff concentration (negative results), followed
subsequently by samples with levels slightly
above the cutoff (positive results) (Huestis, 2002).
This fluctuation between positive and negative
did not occur in all subjects and in those that
did exhibit this pattern, the fluctuation was
generally transitory. Based on this elimination
pattern, it is recommended that programs
using a cannabinoid cutoff of 50 ng/mL allow
an interval of at least three days between the
two negative result samples to establish the
abstinence baseline. It is further recommended
that programs using the 20 ng/mL cannabinoid
cutoff allow an interval of at least five days
between the two negative result samples to
establish the abstinence baseline. If a program’s
testing frequency is greater than every five days
(using the 20 ng/mL cutoff), a total of three or
more negative tests may be required before
the five-day interval is achieved.
C. West Huddleston, III
Director, National Drug Court Institute
National Drug Court Institute
4900 Seminary Road, Suite 320
Alexandria, VA 22311
703.575.9400 ext. 13
703.575.9402 fax
Test your new knowledge. Answer
these true and false questions based
on the Fact Sheet text.
1. The “detection window” means
the length of time a drug will
remain in someone’s system.
2. The choice of testing cutoff
has a profound effect on the
cannabinoid detection window.
3. Despite changes in testing
methodologies, detection times
of cannabinoid metabolites in
urine monitored by immunoas-
say have remained the same
over the past two decades.
4. Chronic users of marijuana
commonly produce a positive
urine drug test result 30 days
after the last smoking episode.
5. Any positive drug test result
following two successive
negative urine drug tests
several days apart indicates
new or recent drug exposure.
6. Since marijuana has such a
prolonged elimination period,
temporarily suspending drug
testing of a client who tests
positive for marijuana is a
good money-saving strategy.
Answers: 1. False; 2. True; 3. False; 4. False; 5. True; 6. False
... Although systematic use of toxicology testing to assess treatment response raises some concerns about feasibility in community settings, less costly methods of detecting abstinence through biological specimen testing and more informed understanding and interpretation of test results has made the detection of abstinence a more viable and practical indicator of treatment progress in community treatment settings (Cary, 2006;Gaalema, Higgins, Bradsreet, Heil, & Bernstein, 2011;Huestis et al., 2011). Given the robust findings showing that abstinence during treatment is a robust predictor of later outcomes, initial abstinence would appear to be an optimal indicator of treatment response. ...
... Parents received weekly family management sessions that included a parent-delivered, abstinence-based CM program involving rewards for abstinence and negative consequences for substance use. Because Δ-9-THC remains detectable at 50ng/ml for up to two weeks and sometimes longer in heavy marijuana users (Cary, 2006), the abstinence contingency did not start until Week 3. During Weeks 1-2, participants in both conditions received $5 vouchers for each specimen provided to encourage compliance with the program. ...
... Urine specimens were collected under staff observation and were tested for 11-nor-delta-9-THC-9-carboxylic acid (THCCOOH), the primary marijuana metabolite. A cutoff level of 50 ng/ml for THCCOOH was used to determine marijuana abstinence (Cary, 2006;Huestis, et al., 2011). Creatinine level (<30 ng/ml) was assessed as a proxy for specimens too dilute for valid testing, and an invalid specimen prompted requests to provide another specimen within 4-24 hours. ...
Full-text available
This study assessed the time to initiation of marijuana abstinence in an adolescent treatment-seeking sample, and identified variables that were predictive of abstinence. Adolescents (N=69), ages 14 to 18 were randomly assigned to one of two 14-week behavioral treatments. Abstinence was measured with twice-weekly urine toxicology plus teen and parent reports. Discrete-time survival and hazard functions were conducted. The majority of adolescents achieved at least 1week of abstinence, and 51% achieved 6weeks of abstinence. Initiation of abstinence occurred by the sixth treatment week for 94% of teens with any abstinence suggesting that alternative, clinical approaches should be considered for those not responding by week 6. Teens with a drug negative urinalysis at intake, and teens that had two parents participating in treatment were more likely to achieve at least 6weeks of abstinence. These findings, if replicated, can be used to inform clinical and research strategies that might lead to enhanced treatment efficacy and cost effectiveness for substance abuse treatment programming.
... ○ Structured Clinical Interview for DSM IV (SCID) part E was used to assess history of alcohol and substance misuse disorders. ○ Urinalysis for cannabis, performed using a commercially available immunoassay test for metabolites of the cannabinoid tetrahydrocannabinol (THC) using the standard cut-off of 50 ng/ml [31]. Psychotic symptoms ○ The positive and negative symptom subscales of the Positive and Negative Syndrome Scale (PANSS) [32]. ...
Full-text available
Background: Cannabis is the most commonly used illicit substance amongst people with psychosis. Continued cannabis use following the onset of psychosis is associated with poorer functional and clinical outcomes. However, finding effective ways of intervening has been very challenging. We examined the clinical and cost-effectiveness of adjunctive contingency management (CM), which involves incentives for abstinence from cannabis use, in people with a recent diagnosis of psychosis. Methods: CIRCLE was a pragmatic multi-centre randomised controlled trial. Participants were recruited via Early Intervention in Psychosis (EIP) services across the Midlands and South East of England. They had had at least one episode of clinically diagnosed psychosis (affective or non-affective); were aged 18 to 36; reported cannabis use in at least 12 out of the previous 24 weeks; and were not currently receiving treatment for cannabis misuse, or subject to a legal requirement for cannabis testing. Participants were randomised via a secure web-based service 1:1 to either an experimental arm, involving 12 weeks of CM plus a six-session psychoeducation package, or a control arm receiving the psychoeducation package only. The total potential voucher reward in the CM intervention was £240. The primary outcome was time to acute psychiatric care, operationalised as admission to an acute mental health service (including community alternatives to admission). Primary outcome data were collected from patient records at 18 months post-consent by assessors masked to allocation. The trial was registered with the ISRCTN registry, number ISRCTN33576045. Results: Five hundred fifty-one participants were recruited between June 2012 and April 2016. Primary outcome data were obtained for 272 (98%) in the CM (experimental) group and 259 (95%) in the control group. There was no statistically significant difference in time to acute psychiatric care (the primary outcome) (HR 1.03, 95% CI 0.76, 1.40) between groups. By 18 months, 90 (33%) of participants in the CM group, and 85 (30%) of the control groups had been admitted at least once to an acute psychiatric service. Amongst those who had experienced an acute psychiatric admission, the median time to admission was 196 days (IQR 82, 364) in the CM group and 245 days (IQR 99, 382) in the control group. Cost-effectiveness analyses suggest that there is an 81% likelihood that the intervention was cost-effective, mainly resulting from higher mean inpatient costs for the control group compared with the CM group; however, the cost difference between groups was not statistically significant. There were 58 adverse events, 27 in the CM group and 31 in the control group. Conclusions: Overall, these results suggest that CM is not an effective intervention for improving the time to acute psychiatric admission or reducing cannabis use in psychosis, at least at the level of voucher reward offered.
... 21, 26 A urinary THCA concentration of $10 ng/mL was used to identify pastweek marijuana use. 27 ...
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Background: Surveys have been instrumental in describing adolescent use of tobacco, electronic cigarettes (e-cigarettes), and marijuana. However, objective biomarker data are lacking. We compared adolescent self-reported use to urinary biomarkers. Methods: From April 2017 to April 2018, adolescents 12 to 21 years old completed an anonymous questionnaire regarding tobacco, e-cigarette, and marijuana use and provided a urine sample. Urine was analyzed for biomarkers cotinine, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, and tetrahydrocannabinolic acid (THCA). Results: Of 517 participants, 2.9% reported using tobacco, 14.3% e-cigarettes, and 11.4% marijuana in the past week. Only 2% reporting no smoking had total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol levels above cutoff (14.5 pg/mL); 2% of non-e-cigarette users had cotinine above cutoff (10 ng/mL); 2% of those denying marijuana use had THCA above cutoff (10 ng/mL). Daily e-cigarette users showed significantly higher median cotinine than nondaily users (315.4 [interquartile range (IQR) 1375.9] vs 1.69 ng/mL [IQR 28.2]; P < .003). Overall, 40% who reported using nicotine-free products had cotinine >10 ng/mL. Pod users' median cotinine was significantly higher than in nonpod users (259.03 [IQR 1267.69] vs 1.61 ng/mL [IQR 16.3]; P < .003). Median THCA among daily marijuana users was higher than in nondaily users (560.1 [IQR 1248.3] vs 7.2 ng/mL [IQR 254.9]; P = .04). Sixty-one percent of those with cotinine >10 ng/mL vs 39% of those with cotinine<10 ng/mL had THCA >10 ng/mL (P < .001). Conclusions: Adolescents' self-report correlated with measured urinary biomarkers, but subjects were unaware of their nicotine exposure. More frequent e-cigarette and pod use correlated with elevated biomarkers. Co-use of tobacco, e-cigarettes, and marijuana was corroborated by higher THCA in those with higher cotinine.
... People who smoke cannabis more than once a day, every day, can test positive at the initial federal cutoff (50 ng/ml) for over 24 days after cessation (165). In infrequent users, a single use will not be detectable after 3-4 days (54). Likewise, even very heavy secondhand exposure to cannabis smoke is unlikely to result in a positive drug test after 12 h (66). ...
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Accurate and reliable measurements of exposure to tobacco products are essential for identifying and confirming patterns of tobacco product use and for assessing their potential biological effects in both human populations and experimental systems. Due to the introduction of new tobacco-derived products and the development of novel ways to modify and use conventional tobacco products, precise and specific assessments of exposure to tobacco are now more important than ever. Biomarkers that were developed and validated to measure exposure to cigarettes are being evaluated to assess their utility for measuring exposure to these new products. Here, we review current methods for measuring exposure to new and emerging tobacco products, such as electronic cigarettes, little cigars, water pipe and cigarillos. Rigorously validated biomarkers specific to these new products are yet to be identified. Here, we discuss the strengths and limitations of current approaches, including whether or not they provide reliable exposure estimates. We provide specific guidance for choosing practical and economical biomarkers for different study designs and experimental conditions. Our goal is to help both new and experienced investigators measure exposure to tobacco products accurately, while avoiding common experimental errors. By identifying the capacity gaps in biomarker research on new and emerging tobacco products, we hope to provide researchers, policy makers and funding agencies with a clear action plan for conducting and promoting research on the patterns of use and health effects of these products.
... 42 Like other studies, we noted that marijuana was the most commonly used drug during pregnancy. [50][51][52][53][54][55][56][57] Our perinatal marijuana rates were higher than the 4.6% noted in the NSDUH 2009 report or the 6% found in a recent study that included 1632 women from four cities across the United States. 43,44 Characteristics of our study population, such as the high proportion of African-American and lower-socioeconomic-status women, likely contribute to our higher rates of perinatal illicit drug and marijuana use. ...
... 42 Like other studies, we noted that marijuana was the most commonly used drug during pregnancy. [50][51][52][53][54][55][56][57] Our perinatal marijuana rates were higher than the 4.6% noted in the NSDUH 2009 report or the 6% found in a recent study that included 1632 women from four cities across the United States. 43,44 Characteristics of our study population, such as the high proportion of African-American and lower-socioeconomic-status women, likely contribute to our higher rates of perinatal illicit drug and marijuana use. ...
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Purpose: To assess use, screening, and disclosure of perinatal marijuana and other illicit drugs during first obstetric visits. Design: Observational study that qualitatively assesses provider screening and patient disclosure of substance use. Setting: Study sites were five urban outpatient prenatal clinics and practices located in Pittsburgh, Pennsylvania. Participants: Pregnant patients and obstetric providers were recruited as participants. Methods: We audio recorded patient-provider conversations during first obstetric visits and obtained patient urine samples for drug analyses. Audio recordings were reviewed for provider screening and patient disclosure of illicit drug use. Urine analyses were compared with audio recordings to determine disclosure. Results: Four hundred and twenty-two pregnant patients provided complete audio recordings and urine samples for analyses. Providers asked about illicit drug use in 81% of the visits. One hundred twenty-three patients (29%) disclosed any current or past illicit drug use; 48 patients (11%) disclosed current use of marijuana while pregnant. One hundred and forty-five samples (34%) tested positive for one or more substances; marijuana was most commonly detected (N = 114, 27%). Of patients who tested positive for any substance, 66 (46%) did not disclose any use; only 36% of patients who tested positive for marijuana disclosed current use. Conclusion: Although marijuana is illegal in Pennsylvania, a high proportion of pregnant patients used marijuana, with many not disclosing use to their obstetric care providers.
Cannabis;case-control;culpability;driving;driving under the influence;DUI;impairment
In Populations, Public Health and the Law, legal scholar Wendy Parmet urges courts to embrace population-based legal analysis, a public health inspired approach to legal reasoning. Parmet contends that population-based legal analysis offers a way to analyze legal issues--not unlike law and economics--as well as a set of values from which to critique contemporary legal discourse. Population-based analysis has been warmly embraced by the health law community as a bold new way of analyzing legal issues. Still, population-based analysis is not without its problems. At times, Parmet claims too much territory for the population perspective. Moreover, Parmet urges courts to recognize population health as an important norm in legal reasoning. What should we do when the insights of public health and conventional legal reasoning conflict? Still in its infancy, population-based analysis offers little in the way of answers to these questions. This Article applies population-based legal analysis to the constitutional problems that arise when states condition public assistance benefits on passing a drug test, thereby highlighting the strengths of the population perspective and exposing its weaknesses.
Since centuries, cannabis is used for recreational, spiritual and medicinal purposes. Today, cannabis is one of the most commonly used illicit substances, also among pregnant women. In the last decades, levels of Δ9-tetrahydrocannabinol in cannabis products have increased, and these higher levels contributed to our interest for investigating the effects of cannabis during pregnancy. The study described in this thesis was embedded within the Generation R Study, a prospective cohort study from foetal life onwards in a multiethnic urban population. In this study, we examined the associations of maternal cannabis use during pregnancy and several offspring outcomes. In order to determine whether cannabis use affects children because of intrauterine exposure, the possible influence of confounding factors should be considered. Moreover, the direct biological effect of intrauterine exposure was addressed by comparing the strength of the associations between maternal and paternal cannabis use during pregnancy and foetal growth using ultrasound measures. Additionally, to determine whether exposure to cannabis has an intrauterine influence or not, the timing of exposure was considered as well, i.e. the comparison between maternal cannabis use only before pregnancy and during pregnancy was made. This manuscript described the determinants of maternal cannabis use during pregnancy. Additionally, it discussed the agreement between maternal self-report of cannabis use during pregnancy and the presence of cannabis metabolites in urine. We addressed the association between maternal and paternal cannabis use and foetal growth and foetal redistribution observed using ultrasound measurements. Finally, this thesis focuses on the relation between parental cannabis use and child behavioural development and verbal and non-verbal cognitive development.
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Cannabis is one of the oldest and most commonly abused drugs in the world. Recently, tremendous advances have been made in our understanding of the endogenous cannabinoid system with the identification of cannabinoid receptors, cannabinoid receptor antagonists, endogenous neurotransmitters, metabolic enzymes, and reuptake mechanisms. These advances have helped us to elucidate the mechanisms of action of cannabis and the side effects and toxicities associated with its use. In addition, potential therapeutic applications are being investigated for the use of smoked cannabis and synthetic THC (dronabinol). Most workplace, military, and criminal justice positive urine drug tests are due to the use of cannabis. In addition, alternative matrices, including saliva, sweat, and hair, are being utilized for monitoring cannabis use in treatment, employment, and criminal justice settings. Experimental laboratory studies have identified cognitive, physiological, and psychomotor effects following cannabis. Epidemiological studies reveal that cannabis is the most common illicit drug world-wide in impaired drivers, and in motor vehicle injuries and fatalities. Driving simulator studies also indicate performance impairment following cannabis use; however, the results of open-and closed-road driving studies and of culpability studies do not consistently document increased driving risk. Clearly a combination of ethanol and cannabis use significantly increases risks. This article reviews the pharmacokinetics and pharmacodynamics of cannabis and places special emphasis on the effects of cannabis on complex tasks such as driving and flying.
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The urinary excretion of the total amount of Δ1-tetrahydrocannabinol (Δ1-THC) metabolites, with special emphasis on Δ1-tetrahydrocannabinol-7-oic acid (Δ1-THC-7-oic acid), was studied in thirteen heavy Cannabis users after smoking administration of Δ1-THC, followed by a four week discontinuation period. The total amount of Δ1-THC metabolites and the levels of Δ1-THC-7-oic acid could be followed up to 25 days after abstinence using EMIT d.a.u. cannabinoid assay and high-performance liquid chromatography (HPLC). The urinary excretion half-life, calculated from the concentrations of Δ1-THC-7-oic acid versus time, ranged from 0.8–9.8 days with a mean (± SD) of 3.0 ± 2.3 days. Most of the Δ1-THC-7-oic acid was excreted as conjugate and only trace amounts of unconjugated Δ1-THC-7-oic acid were detected. The total concentrations of Δ1-THC-7-oic acid in urine were compared to the concentrations of “cross-reacting cannabinoids”, within the linear range of 20–75 ng/mL, obtained in the semiquantitative EMIT d.a.u. cannabinoid assay. The average ratio of “EMIT concentrations”/Δ1-THC-7-oic acid concentrations obtained by HPLC analysis was 1.23 ± 84% (C.V.) for 78 urine samples. A total of 83% of the samples with positive EMIT levels (cutoff 20 ng/mL) was confirmed by HPLC analysis (cutoff 7 ng/mL).
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Proposed changes to the Health and Human Services Guidelines for forensic urine drug testing will lower the required cannabinoid immunoassay cutoff concentration from 100 to 50 micrograms/L. We investigated the effect of this change on the sensitivity, specificity, and efficiency of eight cannabinoid immunoassays: Syva Emit d.a.u. 100; Syva Emit II 100; Syva Emit d.a.u. 50; Syva Emit II 50; Roche Abuscreen Online; Roche Abuscreen radioimmunoassay; Diagnostic Reagents; and Abbott ADx. All specimens also were assayed by gas chromatography/mass spectrometry. Lowering the cutoff concentration from 100 to 50 micrograms/L increased efficiencies and sensitivities for all immunoassays, with minor decreases in specificity (1.0-2.6%). There was a 23.2-53.6% increase in the number of true-positive specimens identified. Thus, lowering the cannabinoid immunoassay cutoff concentration from 100 to 50 micrograms/L resulted in detection of a substantial number of additional true-positive specimens, with an accompanying small increase in unconfirmed positive results.
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Interpretation of marijuana-positive urine tests requires an understanding of the excretion pattern of marijuana metabolites in humans. However, limited urinary excretion data from controlled clinical studies of marijuana use are available. In this study, six subjects smoked a single marijuana cigarette (placebo, 1.75% delta 9-tetrahydrocannabinol [THC], or 3.55% THC) each week while residing on the clinical ward of the Addiction Research Center. Individual urine specimens were collected for 7 days after drug administration and analyzed for 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (THCCOOH) by gas chromatography-mass spectrometry (GC-MS) with a limit of detection of 0.5 ng/mL. Substantial intersubject variability in patterns of THCCOOH excretion was noted between subjects and between doses. Mean THCCOOH concentrations in the first urine collections were 47 +/- 22.3 ng/mL and 75.3 +/- 48.9 ng/mL after the 1.75 and 3.55% THC cigarettes, respectively. Mean peak urine THCCOOH concentrations averaged 89.8 +/- 31.9 ng/mL and 153.4 +/- 49.2 ng/mL after smoking of approximately 15.8 mg and 33.8 mg THC, respectively. The mean times of peak urine concentration were 7.7 +/- 0.8 h after the 1.75% THC and 13.9 +/- 3.5 h after the 3.55% THC dose. Mean GC-MS THCCOOH detection times for the last positive urine sample after the smoking of a single 1.75 or 3.55% THC cigarette were 33.7 +/- 9.2 h and 88.6 +/- 9.5 h, respectively, when a 15-ng/mL cutoff concentration was used. An average of 93.9 +/- 24.5 micrograms THCCOOH (range, 34.6-171.6 micrograms) was excreted by each subject during the 7-day period after smoking of a single 1.75% THC cigarette. The average amount of THCCOOH excreted in the same time period after the high dose was 197.4 +/- 33.6 micrograms (range, 107.5-305.0 micrograms). This represented an average of only 0.54 +/- 0.14% and 0.53 +/- 0.09% of the original amount of THC in the low-and high-dose cigarettes, respectively. These data provide a detailed complication of THCCOOH concentrations in urine after administration of marijuana that may aid in the interpretation of urine cannabinoid results.
Frequent smoking of cannabis (marijuana) has been shown to be associated with a decline in social, mental, and perceptual skills and, during adolescence, with maladaptive emotional development. Urinalysis for the detection of such use can be a useful tool for the physician responsible for treatment and counseling of adolescents who develop habitual use of marijuana. Primary methods for urinalysis detection of cannabis use include the homogeneous enzyme immunoassay (EMIT) and the radioimmunoassay. These and other methods are discussed along with the issues of "false" results (both positive and negative) and the "limits of interpretation" that can be placed on a positive urine result. The pharmacokinetics and metabolism of the active constituents of cannabis are described as well as the interpretation of urinalysis results as they relate to use patterns. Guidelines are presented for the primary care physician for selecting candidates for such testing and for the use of such tests in the treatment or counseling of adolescents for whom marijuana abuse has become a psychological and social problem.
The urinary excretion patterns of 86 chronic cannabis users were examined after their last cannabis use by two common screening methods, the semiquantitative EMIT-d.a.u. and the qualitative EMIT-st (Syva Company). We demonstrated that under very strictly supervised abstinence, chronic users can have positive results for cannabinoids in urine at 20 ng/ml or above on the EMIT-d.a.u. assay for as many as 46 consecutive days from admission, and can take as many as 77 days to drop below the cutoff calibrator for 10 consecutive days. For all subjects, the mean excretion time was 27 days. Subject excretion patterns were clearly biphasic, with initial higher rates of excretion not sustained. During the subsequent period of leveling off, most subjects had one or more separate sequences of cannabinoid-negative urine test results, lasting a mean of 3 days each and followed by at least one positive result. Demographic, body type, and drug history variables proved to be only moderate predictors of excretion patterns. Findings were discussed in the context of potential clinical and forensic application.
The authors present a case report of the presence of urinary cannabinoids during 21 days of supervised abstinence from chronic marijuana use and provide data on 6 similar cases. They discuss the theoretical implications of the persistence of cannabinoids.
Marijuana continues to be one of the most widely used illicit drugs in this country. Unlike most other drugs, it is persistent in the body and elimination occurs only gradually. Using the Syva EMIT Cannabinoid Assay test, a readily available semiquantitative immunochemical urine test for marijuana metabolites, a group of ten chronic marijuana users was monitored while hospitalized. The results of the monitoring are presented as are two representative case reports. Implications regarding the interpretation of results and interpretation of "significant" urinary marijuana levels are discussed. Specific implications for use in treatment programs and general primary care settings are also discussed.
The apparent half-life of excretion of cannabinoids was calculated from their concentration in the urine of 27 psychotic patients. The best estimate was about 4 days but the range was too wide to be of use in predicting time to total clearance from the body of any randomly chosen patient.