Acute Effects of 3,4-Methylenedioxymethamphetamine and Methylphenidate on Circulating Steroid Levels in Healthy Subjects

Abstract

3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') and methylphenidate are widely used psychoactive substances. MDMA primarily enhances serotonergic neurotransmission, and methylphenidate increases dopamine but has no serotonergic effects. Both drugs also increase norepinephrine, resulting in sympathomimetic properties. Here we studied the effects of MDMA and methylphenidate on 24-h plasma steroid profiles. Sixteen healthy subjects (eight men, eight women) were treated with single doses of MDMA (125 mg), methylphenidate (60 mg), MDMA + methylphenidate, and placebo on four separate days using a cross-over study design. Cortisol, cortisone, corticosterone, 11-dehydrocorticosterone, aldosterone, 11-deoxycorticosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstendione, and testosterone were repeatedly measured up to 24-h using liquid-chromatography tandem mass-spectroscopy. MDMA significantly increased the plasma concentrations of cortisol, corticosterone, 11-dehydrocorticosterone, and 11-deoxycorticosterone and also tended to moderately increase aldosterone levels compared with placebo. MDMA also increased the sum of cortisol + cortisone and the cortisol/cortisone ratio, consistent with an increase in glucocorticoid production. MDMA did not alter the levels of cortisone, DHEA, DHEAS, androstendione, or testosterone. Methylphenidate did not affect any of the steroid concentrations, and it did not change the effects of MDMA on circulating steroids. In summary, the serotonin releaser MDMA has acute effects on circulating steroids. These effects are not observed after stimulation of the dopamine and norepinephrine systems with methylphenidate. The present findings support the view that serotonin rather than dopamine and norepinephrine mediates the acute pharmacologically-induced stimulation of the hypothalamic-pituitary-adrenal axis in the absence of other stressors. © 2014 S. Karger AG, Basel.

Full text

E-Mail karger@karger.com
Original Paper
Neuroendocrinology 2014;100:17–25
DOI: 10.1159/000364879
Acute Effects of 3,4-Methylenedioxymethamphetamine
and Methylphenidate on Circulating Steroid Levels in
Healthy Subjects
Julia Seibert a Cédric M. Hysek b Carlos A. Penno a Yasmin Schmid b
Denise V. Kratschmar a Matthias E. Liechti b Alex Odermatt a
a Swiss Center for Applied Human Toxicology and Division of Molecular and Systems Toxicology, Department of Pharmaceutical
Sciences, University of Basel, and
b Psychopharmacology Research Group, Division of Clinical Pharmacology and Toxicology,
Department of Biomedicine and Department of Clinical Research, University Hospital and University of Basel, Basel , Switzerland
repeatedly measured up to 24 h using liquid chromatogra-
phy-tandem mass spectroscopy. MDMA significantly in-
creased the plasma concentrations of cortisol, corticoste-
rone, 11-dehydrocorticosterone, and 11-deoxycorticoste-
rone and also tended to moderately increase aldosterone
levels compared with placebo. MDMA also increased the
sum of cortisol + cortisone and the cortisol/cortisone ratio,
consistent with an increase in glucocorticoid production.
MDMA did not alter the levels of cortisone, DHEA, DHEAS,
androstenedione, or testosterone. Methylphenidate did not
affect any of the steroid concentrations, and it did not
change the effects of MDMA on circulating steroids. In sum-
mary, the serotonin releaser MDMA has acute effects on cir-
culating steroids. These effects are not observed after stim-
ulation of the dopamine and norepinephrine systems with
methylphenidate. The present findings support the view
that serotonin rather than dopamine and norepinephrine
mediates the acute pharmacologically induced stimulation
of the hypothalamic-pituitary-adrenal axis in the absence of
other stressors.
© 2014 S. Karger AG, Basel
Key Words
MDMA · Methylphenidate · Steroid · Cortisol · Aldosterone ·
Testosterone
Abstract
3,4-Methylenedioxymethamphetamine (MDMA, ‘ecstasy’)
and methylphenidate are widely used psychoactive sub-
stances. MDMA primarily enhances serotonergic neuro-
transmission, and methylphenidate increases dopamine
but has no serotonergic effects. Both drugs also increase
norepinephrine, resulting in sympathomimetic properties.
Here we studied the effects of MDMA and methylphenidate
on 24-hour plasma steroid profiles. 16 healthy subjects (8
men, 8 women) were treated with single doses of MDMA
(125 mg), methylphenidate (60 mg), MDMA + methylpheni-
date, and placebo on 4 separate days using a cross-over
study design. Cortisol, cortisone, corticosterone, 11-dehy-
drocorticosterone, aldosterone, 11-deoxycorticosterone,
dehydroepiandrosterone (DHEA), dehydroepiandrosterone
sulfate (DHEAS), androstenedione, and testosterone were
Received: March 19, 2014
Accepted after Revision: May 26, 2014
Published online: June 5, 2014
Matthias E. Liechti
Division of Clinical Pharmacology and Toxicology
University Hospital Basel, Hebelstrasse 2
CH–4031 Basel (Switzerland)
E-Mail matthias.liechti  @  usb.ch
Alex Odermatt
Division of Molecular and Systems Toxicology
Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50
CH–4056 Basel (Switzerland)
E-Mail alex.odermatt
 @  unibas.ch
© 2014 S. Karger AG, Basel
0028–3835/14/1001–0017$39.50/0
www.karger.com/nen
J. Seibert, C.M. Hysek, M.E. Liechti and A. Odermatt contributed
equally to this work.
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18
Introduction
Many recreational drugs activate the hypothalamic-
pituitary-adrenal (HPA) axis to release adrenocortico-
tropic hormone (ACTH) and corticosteroids
[1] . The
neurochemical mechanisms involved in HPA axis acti-
vation depend on the particular drug and mostly involve
corticotropin-releasing factor stimulation in the hypo-
thalamus
[1–3] . HPA axis activation by cocaine and am-
phetamine and its derivatives is thought to be mediated
by increases in brain monoamines, including dopamine
(DA), norepinephrine (NE), and serotonin (5-hydroxy-
tryptamine, 5-HT)
[1] . Few studies have examined
which of these monoamines contribute the most to HPA
axis activation in animals
[1] , and even less data are
available for humans. For example, cocaine inhibits the
uptake of all three monoamines (DA, NE, and 5-HT),
and all three may be involved in cocaine-induced HPA
axis activation. Dopaminergic and adrenergic receptor
antagonists reduced the corticosterone response to co-
caine in rodents
[4–6] . Additionally, the blockade of
5-HT receptors also decreased the ACTH response to
cocaine in rats
[5] .
3,4-Methylenedioxymethamphetamine (MDMA; ‘ec-
stasy’) primarily releases 5-HT in the brain via the sero-
tonin transporter (SERT) and NE via the NE transporter
(NET)
[7] . Methylphenidate is an amphetamine deriva-
tive used for the treatment of attention-deficit/hyperac-
tivity disorder and misused as a cognitive enhancer and
recreationally. In contrast to MDMA, methylphenidate
only elevates the levels of DA and NE by inhibiting the
DA transporter and NET
[8] . Thus, both MDMA and
methylphenidate share an enhancing effect on NE neuro-
transmission, resulting in sympathomimetic and psycho-
stimulant effects
[9] , but they are otherwise indirect sero-
tonergic or dopaminergic agonists, making them phar-
macological tools to evaluate the role of 5-HT and DA as
activators of the HPA axis.
Several studies evaluated the stimulant effects of
MDMA on the HPA axis in humans [for reviews, see
10,
11] . Plasma cortisol has been shown to be increased after
MDMA administration in many human laboratory
studies
[12–15] and in recreational ecstasy users follow-
ing MDMA administration in a club setting
[16 , 17] .
Small laboratory studies also previously reported
MDMA-induced increases in ACTH
[18] and dehydro-
epiandrosterone (DHEA)
[12] . A trend toward an in-
crease in testosterone was also found in subjects who
used MDMA at a dance club
[16] . However, the effects
of MDMA on a wider range of corticosteroids have not
yet been studied in humans. Therefore, we evaluated the
acute effects of predominantly 5-HT activation using
MDMA or predominantly DA activation using methyl-
phenidate or MDMA + methylphenidate on changes in
the plasma concent rat ion of a series of s teroids over 24h
in healthy subjects. Specifically, we measured the plas-
ma levels of glucocorticoids (cortisol, cortisone, corti-
costerone, and 11-dehydrocorticosterone), mineralo-
corticoids (aldosterone and 11-deoxycorticosterone),
and androgens (DHEA, DHEA sulfate (DHEAS), an-
drostenedione, and testosterone). Cortisol is the main
active glucocorticoid and a major stress hormone. It is
converted to the inactive metabolite cortisone. Corti-
costerone is also a potent activator of glucocorticoid and
mineralocorticoid receptors, but it is present at 10- to
20-times lower concentrations than cortisol in humans.
11-Deoxycorticosterone is a precursor of corticosterone
and aldosterone and exhibits mineralocorticoid activity
[19] . Mineralocorticoids increase renal sodium absorp-
tion and blood pressure. Androgens may modulate the
addictive effects of drugs of abuse
[12, 2 0 , 21] . We hy-
pothesized that methylphenidate and MDMA would
differentially affect the plasma levels of these steroids
based on their different pharmacological profiles.
M e t h o d s
Study Design
The study used a double-blind, placebo-controlled, cross-over
design with four experimental test sessions (placebo-placebo,
methylphenidate-placebo, placebo-MDMA, and methylpheni-
date-MDMA) performed in counterbalanced order according to a
Latin square randomization scheme. All of the subjects received all
of the study treatments in a within-subjects study design. The
washout periods between sessions were at least 10 days. The study
was conducted in accordance with the Declaration of Helsinki and
International Conference on Harmonization Guidelines in Good
Clinical Practice and approved by the local Ethics Committee and
Swiss Agency for Therapeutic Products (Swissmedic). The study
was registered at ClinicalTrials.gov: http://clinicaltrials.gov/ct2/
show/NCT01465685. All of the subjects provided written in-
formed consent.
P a r t i c i p a n t s
Sixteen healthy subjects (8 men and 8 women; mean ± SD age
24.8 ± 2.6 years) were recruited from the University of Basel cam-
pus. The exclusion criteria were acute or chronic physical illness,
psychiatric disorders, smoking, and a lifetime history of using il-
licit drugs more than 5 times, with the exception of past cannabis
use. The use of any illicit drugs, including cannabis, within the past
2 months or during the study period was prohibited. We per-
formed urine drug tests at screening and before each test session
using Triage
® 8 (Biosite, San Diego, Calif., USA). Female partici-
pants were investigated during the follicular phase of their men-
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DOI: 10.1159/000364879
19
strual cycle (days 2–14) to account for cyclic changes in the reac-
tivity to amphetamines. A detailed description of the participants
has been previously published
[9] .
Study Procedures
Methylphenidate (60 mg, Ritalin
® ; Novartis, Bern, Switzerland)
or placebo was administered orally at 08:
00 h. MDMA (125 mg,
racemic MDMA hydrochloride; Lipomed, Arlesheim, Switzerland)
or placebo was administered orally at 09:
00 h. A standardized lunch
was served at 12:
00 h, and the subjects were sent home at 18: 00 h.
The day following each test session, the participants returned to the
research ward at 09:
00 h for the collection of the 24-hour blood
sample.
The subjects did not engage in any physical activity and
were resting in hospital beds during the test session. Blood samples
for the analysis of plasma steroid hormone levels (cortisol, corti-
sone, corticosterone, 11-dehydrocorticosterone, 11-deoxycortico-
sterone, aldosterone, DHEA, DHEA-S, androstenedione, and tes-
tosterone) were collected 1 h prior to MDMA or placebo adminis-
tration and 0, 0.33, 0.67, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, and 24 h
following the administration of MDMA or placebo. The psychotro-
pic and autonomic effects of MDMA and methylphenidate from
the present study have been presented elsewhere
[9] .
Steroid Quantification
A detailed description of the materials, procedure, and
method validation is included in the see online supplementary
material (for all online suppl. material, see www.karger.com/
doi/10.1159/000364879). Briefly, plasma samples (1 ml) were
mixed with 200 μl precipitation solution (0.8
M zinc sulfate in wa-
ter/methanol and deuterium-labeled aldosterone, cortisol, corti-
costerone, and testosterone as internal standards), diluted with
water to 2 ml and centrifuged again. The supernatants were sub-
jected to Oasis HBL SPE cartridges for purification. The samples
were reconstituted in 25 μl methanol. Steroids were separated and
quantified by ultra-pressure liquid chromatography-tandem mass
spectroscopy (UPLC-MS/MS) using an Agilent 1290 UPLC cou-
pled to an Agilent 6490 triple quadrupole MS equipped with an
electrospray ionization source (Agilent Technologies, Basel,
Switzerland). The separation of analytes was achieved using a re-
verse-phase column (ACQUITY UPLC
TM BEH C
18 , 1.7 μm, 2.1,
150 mm; Waters, Wexford, Ireland). Mass Hunter software (Agi-
lent Technologies) was used for data acquisition and analysis. For
method validation, see online supplementary material.
Statistical Analyses
Peak concentration (C
max ) values were determined for all
repeated measures. Repeated-measures analyses of variance
( ANOVAs) with the within-subject factors MDMA (MDMA vs.
placebo) and methylphenidate (methylphenidate vs. placebo), fol-
lowed by the Tukey post hoc tests based on significant main effects
of interactions in the ANOVA were used to assess differences in
the effect of the different treatment conditions. Associations were
assessed using Spearman’s rank correlations. One subject was ex-
cluded from the correlational analyses because of missing values.
Because the effects of MDMA were similar regardless of whether
MDMA was administered alone or combined with methylpheni-
date, the data were pooled for the correlational analyses (n = 30).
The significance level was set to p= 0.05. The statistical analysis
was performed using R project statistical packages (R Foundation
for Statistical Computing, Vienna, Austria).
R e s u l t s
The peak levels of plasma steroid hormone concentra-
tions and statistics are shown in table1 . MDMA signifi-
cantly increased the plasma levels of the glucocorticoids
cortisol, corticosterone, and 11-dehydrocorticosterone
and mineralocorticoid 11-deoxycorticosterone compared
with placebo ( fig.1 a, c–e) but not the glucocorticoid cor-
tisone ( fig.1 b). MDMA also significantly increased the
sum of cortisol + cortisone and cortisol/cortisone ratio
( table1 ). The sum of corticosterone + 11-dehydrocortico-
sterone was also significantly elevated (data not shown),
further supporting the increase in glucocorticoid produc-
tion. The levels of the mineralocorticoid aldosterone were
increased by MDMA (significant main effect) but this ef-
fect was only significant for the MDMA + methylpheni-
date condition compared with placebo ( fig.1 f). MDMA
did not significantly alter the circulating levels of the an-
drogens DHEA, DHEAS, androstenedione, or testoster-
one ( fig.2 a–e). For unknown reasons the absolute values
obtained for DHEAS were lower than expected, allowing
qualitative comparison only. Methylphenidate did not af-
fect any of the measured glucocorticoid, mineralocorti-
coid, or androgen hormones compared with placebo
( fig.1 , 2 ). Administration of MDMA + methylphenidate
led to similar hormonal responses compared with MDMA
alone ( fig.1 , 2 ), with the exception of a more robust and
significant increase in aldosterone. There were no interac-
tive effects of MDMA and methylphenidate on steroid
levels. As expected, testosterone levels were lower in wom-
en than in men. No sex differences were observed in the
effects of the drugs on steroid levels. However, significant
positive correlations were found between the MDMA-in-
duced peak elevation of 11-deoxycorticosterone and aldo-
sterone and the peak increase in systolic blood pressure
(R
s = 0.38 and 0.40, respectively, both p< 0.05, n= 30) [9] .
None of the steroid levels (peak or area under the concen-
tration-time curve changes from baseline) correlated with
the simultaneously recorded psychotropic effects of
MDMA including ‘good drug effects’, ‘drug liking’, ‘drug
high’, ‘happy’, and ‘stimulated’ that have been reported
previously
[9] . The time from MDMA administration to
C
max for cortisol, corticosterone, 11-dehydrocorticoster-
one, 11-deoxycorticosterone, and aldosterone was 2.1 ±
0.8, 1.8 ± 0.6, 2.0 ± 0.6, 1.5 ± 0.5 h and 2.1 ± 1.5 h (mean±
SD), respectively. The time to C
max for MDMA was 2.4 ±
0.4 h
[9] . The MDMA-induced acute increases in circulat-
ing steroids generally disappeared within 6 h after drug
administration. The plasma levels of cortisol, determined
by UPLC-MS/MS (present findings) or radioimmunoas-
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say [9] , at the 2 h time point after MDMA administration
were significantly correlated across all measurements
(R
s = 0.77, p< 0.001, respectively, n= 64).
Discussion
The present study provides insights into the acute ef-
fects of two sympathomimetic drugs or pharmacological
stressors on the plasma levels of a series of steroids in
healthy humans. MDMA increased the plasma levels of
the glucocorticoid cortisol. MDMA also increased the
plasma levels of corticosterone and the inactive steroid
11-dehydrocorticosterone, which is known to change in
parallel with cortisol
[22] . Although circulating concen-
trations of corticosterone are lower than those of cortisol,
a significantly increased ratio of corticosterone to cortisol
was observed in the brain as a result of differential trans-
port by the P-glycoprotein at the blood-brain barrier
[23] .
MDMA had no effect on the inactive cortisol metabolite
cortisone, which is produced by 11β-hydroxysteroid de-
hydrogenase (11β-HSD) type 2, mainly in the kidney, and
the reverse reaction is catalyzed by 11β-HSD1
[24] . Nota-
bly, MDMA increased both the sum of cortisol + cortisone
levels and cortisol/cortisone ratio, suggesting an increase
in HPA axis stimulation and possibly reduced or saturated
11β-HSD2 enzyme function
[25] . A high cortisol/corti-
sone ratio has also been observed after acute ACTH ad-
ministration and in patients with chronic ACTH hyperse-
cretion
[25] . In contrast, a low cortisol/cortisone ratio
characterizes adrenal insufficiency
[26] . MDMA also in-
creased the levels of the mineralocorticoids 11-deoxycor-
ticosterone and aldosterone, an effect that reached signif-
icance for the latter only when MDMA was co-adminis-
tered with methylphenidate. The mineralocorticoids,
including aldosterone and 11-deoxycorticosterone, phys-
iologically increase renal sodium absorption and blood
pressure. We observed a significant association between
MDMA-induced increases in mineralocorticoids and in-
creases in systolic blood pressure. However, MDMA does
not alter plasma sodium levels or plasma osmolality as
shown in a previous study
[27] . This finding would be well
explained by the fact that MDMA also increases plasma
arginine vasopressin
[27, 28] , which increases water reten-
tion and therefore has similar effects on blood pressure as
aldosterone but opposite effects on plasma sodium levels.
In fact, MDMA tended to increase urine osmolality
[27] .
In the present study, MDMA did not affect the concentra-
tions of the androgens DHEA, DHEAS, androstenedione,
or testosterone. Methylphenidate alone did not increase
Table 1. Absolute peak plasma steroid concentrations and statistics
Placebo-
placebo
(mean ± SE)
Placebo-
MDMA
(mean ± SE)
Methylphenidate-
placebo
(mean ± SE)
Methylphenidate-
MDMA
(mean ± SE)
MDMA Methylphenidate Methylpheni date ×
MDMA
 F1,16 p value F1,16 p value F1,16 p value
Glucocorticoids
Cortisol, nM463±53 770±45*** 556±54 765±43*** 43.47 <0.001 3.05 0.10 2.39 0.14
Cortisone, nM36.7±1.8 40.9±2.7 43.4±3.0 42.6±2.2 0.34 0.57 3.65 0.08 1.39 0.26
Corticosterone, nM8.4±1.5 29.7±2.4*** 12.8±2.4### 26.1±3.6*** 46.35 <0.001 0.05 0.82 2.54 0.13
11-Dehydrocorticosterone, nM2.0±0.3 5.1±0.4*** 2.9±0.4### 5.2±0.5*** 45.49 <0.001 4.75 0.05 1.65 0.22
Cortisol + cortisone 499±52 796±45*** 582±54### 802±43*** 43.47 <0.001 3.05 0.10 1.46 0.25
Cortisol/cortisone ratio 15.8±1.7 24.8±1.5*** 16.6±1.5### 23.21±1.46*** 26.77 <0.001 0.29 0.60 1.24 0.28
Mineralocorticoids
Aldosterone, nM0.16±0.04 0.25±0.06 0.17±0.04 0.33±0.11*5.56 0.03 1.02 0.33 1.14 0.30
11-Deoxycorticosterone, nM0.21±0.06 0.42±0.08** 0.26±0.07#0.44±0.08*** 14.57 0.002 0.86 0.37 0.16 0.69
Androgens
DHEA, nM24.7±6.6 24.6±3.5 19.7±2.4 23.7±3.4 0.69 0.42 0.95 0.35 0.27 0.61
DHEAS, nM787±75 1.036±103 954±140 1,032±98 2.81 0.11 1.74 0.21 1.28 0.28
Androstenedione, nM6.0±1.1 7.5±1.0 6.4±0.8 7.3±0.9 3.69 0.07 0.13 0.73 0.78 0.39
Testosterone in women, nM0.59±0.25 0.55±0.14 0.45±0.19 0.57±0.10 0.07a0.80 0.65a0.45 0.45a0.53
Testosterone in men, nM11.8±4.4 13.0±3.9 14.0±4.3 13.0±4.0 0.00a0.97 2.35a0.17 3.03a0.13
Values are peak concentrations (mean ± SEM) of 16 subjects. *For p< 0.05, **for p< 0.01, and ***for p< 0.001 compared to placebo-placebo. #For
p< 0.05, and ###for p< 0.001 compared to placebo-MDMA (Tukey post hoc tests based on significant main effects in the ANOVAs).
aF1,7 (8 instead of 16 subjects).
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Cortisone (nM)
0
–1 0123 4
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6824
10
20
30
40
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Cortisol (nM)
0
–10 123 4
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6824
200
400
600
800
1,000
Corticosterone (nM)
0
–10 123 4
Time (h)
6824
10
20
30
40
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Aldosterone (nM)
0
–10 123 4
Time (h)
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0.2
0.3
0.4
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11-Dehydrocorticosterone (nM)
0
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6
8
10
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0.4
0.5
CYP11B1/2 Placebo-MDMA
Methylphenidate-MDMA
Methylphenidate-placebo
Placebo-placebo
a b
cd
e f
Fig. 1. a–f Effects of MDMA and methylphenidate on plasma con-
centration-time profiles of glucocorticoids and mineralocorti-
coids. The values are expressed as mean ± SEM in 16 subjects.
MDMA was administered at t= 0 h. Methylphenidate was admin-
istered at t= –1 h. MDMA significantly increased the plasma con-
centrations of cortisol (
a ), corticosterone ( c ), 11-dehydrocortico-
sterone (
d ), and weak mineralocorticoid 11-deoxycorticosterone
(
e ) but not the non-bioactive glucocorticoid cortisone ( b ). MDMA
also tended to moderately increase the plasma levels of the miner-
alocorticoid aldosterone (
f ). Similar changes in plasma steroid lev-
els were induced regardless of whether MDMA was administered
alone or combined with methylphenidate (
a–f ). In contrast to
MDMA, methylphenidate did not alter the plasma levels of any of
the steroids (
a–f ). CYP= Cytochrome P450.
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DHEA (nM)
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tration-time profiles of androgens. The values are expressed as the
mean ± SEM in 16 subjects (8 subjects for testosterone). MDMA
was administered at t= 0 h. Methylphenidate was administered at
t= –1 h. MDMA did not significantly alter the plasma concentra-
tions of DHEA (
a
), DHEAS (
b
), androstenedione (
c
), or testos-
terone in men (
d
) or women (
e
). Similar changes in plasma an-
drogen levels were induced regardless of whether MDMA was ad-
ministered alone or combined with methylphenidate (
a–e
).
Similarly, methylphenidate did not alter the plasma levels of any
of the androgens (
a–e
). 17β-HSD = 17β-Hydroxysteroid dehy-
drogenase.
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Effects of MDMA and Methylphenidate
on Steroid Hormones
Neuroendocrinology 2014;100:17–25
DOI: 10.1159/000364879
23
the concentrations of any of the steroids measured. Co-
administration of MDMA + methylphenidate produced a
similar hormonal response to MDMA alone.
Several previous laboratory studies have documented
similar and maximal 2-fold (50–100%) increases in plas-
ma cortisol levels in response to comparable doses of
MDMA
[12–15] . In contrast, 2- to 8-fold increases in cor-
tisol levels were observed in dance clubbers who used
MDMA while physically active
[16, 17, 29] . Moderate
MDMA-induced elevations of DHEA were seen in a pre-
vious laboratory study
[12] . The effects of MDMA on all
of the other steroids reported herein have not been previ-
ously described in a placebo-controlled setting. A non-
significant trend toward an increase in plasma testoster-
one levels has been reported in healthy subjects who used
MDMA at a dance club
[16] . In contrast, we did not ob-
serve any effects of MDMA on testosterone levels in our
placebo-controlled study.
Methylphenidate at an oral dose of 60 mg did not affect
steroid levels in the present study. Similarly, oral methyl-
phenidate at a dose of 20 mg did not alter plasma cortisol
levels in healthy subjects
[30, 31] . In contrast, intravenous
methylphenidate at doses of 10 mg (0.12–0.15 mg/kg) or
0.3 mg/kg significantly increased cortisol levels in healthy
subjects
[32] . Related catecholaminergic substances, such
as amphetamine and methamphetamine, have also been
shown to elevate cortisol levels in some studies
[33–36]
but not others
[14] . A single dose of the NET inhibitor
reboxetine also increased cortisol levels
[37] , particularly
in subjects who scored high on subclinical depression
[38] . Chronic treatment with methylphenidate increased
the levels of DHEA and DHEAS but not cortisol in chil-
dren with attention-deficit/hyperactivity disorder
[39] .
There are several possible explanations why methylphe-
nidate at a relatively high single oral dose of 60 mg
[40,
41] did not affect steroid levels in the present study. For
example, cortisol levels are typically highest in the morn-
ing, which is when methylphenidate was administered in
our study. In contrast, in studies that reported significant
increases in cortisol, methylphenidate was administered
in the evening, when cortisol levels are typically low
[32] .
Additionally, physical activity may have enhanced the re-
sponse to stimulant drugs in some previous studies
[29] ,
whereas our subjects were resting. Finally, a significant
response was observed with intravenous but not oral ad-
ministration, possibly because of faster changes associ-
ated with the mode of drug exposure.
Pharmacologically, MDMA activates the 5-HT system,
and methylphenidate does not
[7] . MDMA but not meth-
ylphenidate increased plasma prolactin levels
[9] , which is
a clinical marker of serotonergic activity
[42] . The present
study, therefore, indicates that 5-HT plays a crucial role in
mediating activation of the HPA axis. In rats, the MDMA-
induced release of ACTH or corticosterone has been
shown to involve 5-HT release and 5-HT
1 and 5-HT
2 re-
ceptor stimulation
[43, 44] . We previously showed that
MDMA-induced increases in plasma cortisol in humans
were blocked by the SERT/NET inhibitor duloxetine
[13] ,
which blocks the interaction of MDMA with the SERT
and NET and the resulting MDMA-induced transporter-
mediated release of 5-HT and NE
[7] , but were not blocked
by the NET inhibitor reboxetine
[13] , which only blocks
the MDMA-induced release of NE
[45] .
Additionally, MDMA and the 5-HT releaser meta-
chlorophenylpiperazine increased plasma cortisol levels,
whereas amphetamine, which activates catecholamines
more similarly to methylphenidate, did not
[14] . Selective
activation of the 5-HT system by acute administration of
the SERT inhibitor citalopram also increased plasma and
salivary cortisol levels
[46] . Six-day treatment with citalo-
pram but not the NET inhibitor reboxetine also increased
waking salivary cortisol levels
[47] . Finally, significant as-
sociations have been reported between polymorphisms in
the genes that encode the SERT and HPA axis reactivity
[48] . Thus, these findings indicate a role for 5-HT in the
mediation of MDMA-induced HPA axis stimulation in
humans but little or no role for NE. Additionally, MDMA
releases 5-HT from peripheral non-neuronal tissues di-
rectly into the blood plasma
[49] and 5-HT has been
shown to directly stimulate aldosterone secretion by glo-
merulosa cells
[50] .
One important issue is the clinical relevance of MDMA’s
effects on corticosteroids. Steroids are involved in a wide
range of central and peripheral physiological functions re-
lated to mood, cognition, adaptation to stress, immune
function, and others. In the context of recreational drug
use, cortisol, DHEA, and testosterone may contribute to
or modulate substance-induced acute psychotropic and
reinforcing effects
[12, 20, 21] . For example, MDMA-in-
duced increases in plasma cortisol levels have previously
been shown to correlate with subjective drug liking in re-
sponse to MDMA in a laboratory study
[12] . Stress-in-
duced increases in cortisol were also correlated with posi-
tive mood responses to amphetamine
[51] . Nonetheless,
we found no associations between plasma steroid levels
and any of the previously reported psychotropic effects of
MDMA in the present study
[9] or in our previous work
[13] . It is possible that we missed a true association be-
cause of the small study size. It is also possible that the
subjective and some endocrine responses were maximal
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Seibert/Hysek/Penno/Schmid/
Kratschmar/Liechti/Odermatt
Neuroendocrinology 2014;100:17–25
DOI: 10.1159/000364879
24
and therefore similar in most subjects (low between-sub-
ject variability). For example, such a lack of between-sub-
jects correlations has previously been documented for
correlations between MDMA plasma levels and autonom-
ic effects
[52] . The pleasurable effects of amphetamine and
methamphetamine in humans also did not change when
cortisol levels were increased pharmacologically
[53] or
lowered by metyrapone administration prior to metham-
phetamine administration
[33] . As noted above, MDMA-
induced elevations of mineralocorticoids may also con-
tribute to regulation of the hypertensive effects of MDMA.
Corticosteroids may also facilitate the development of hy-
perthermia associated with amphetamines, a potentially
fatal complication of recreational ecstasy use
[54, 55] . In
rats, adrenalectomy or administration of a glucocorticoid
receptor antagonist suppressed methamphetamine- and
MDMA-induced increases in body temperature
[56–58] .
Human data are lacking, but MDMA-induced elevations
of steroids may contribute to the clinical toxicity of ec-
stasy
[16, 29] . Finally, repeated HPA axis stimulation by
MDMA may contribute to chronic toxicity
[11, 17, 29] ,
including the deficits in neurocognitive function de-
scribed in heavy ecstasy users
[59] .
The present study has several limitations. First, we used
only single doses of the drugs. However, the selected dos-
es were high and produced pronounced and comparable
sympathomimetic and drug-typical psychotropic effects
[9] . Second, we did not assess corticotropin-releasing fac-
tor or ACTH levels to describe the drugs’ effects on other
mediators within the HPA axis. Instead, we provided the
full profiles of ten steroids. Specifically, we included corti-
costerone, which is the biologically relevant glucocorti-
coid in rodents, the mineralocorticoid aldosterone, and
androgens, which may play a role in mood regulation.
In conclusion, the MDMA- but not methylphenidate-
induced effects on plasma steroids are consistent with a
role for 5-HT in drug-induced HPA axis stimulation in
the absence of other (psychosocial) stressors. Remaining
to be investigated are whether and how the different ste-
roids contribute to the acute and chronic effects of these
psychoactive drugs.
Acknowledgements
This study was supported by the Swiss Centre of Applied Human
Toxicology (to A. Odermatt), Swiss National Science Foundation
(31003A_140961 to A. Odermatt and 32323B_144996 and
320030_149493 to M.E. Liechti), and University of Basel (DPH 2064
to C.M. Hysek). We thank Nathalie Schillinger and Nicole Meyer for
study management and M. Arends for manuscript editing.
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