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SLEEP DISORDERS (RM BENCA, SECTION EDITOR)
The Link Between Suicide and Insomnia: Theoretical
Mechanisms
W. Vaughn McCall & Carmen G. Black
#
Springer Science+Business Media New York 2013
Abstract Insomnia has been established as a risk factor for
depression and mental illness for decades, but a growing
body of evidence has recently exposed insomnia to be an
independent risk factor for suicide that encom passes all age
ranges. This discovery has invigorated investigation to elu-
cidate the relationship between insomnia and suicide, and
over 20 studies reinforcing this association in adults have
been published since 2010 alone. This article analyzes rele-
vant research and emphasizes studies published within the
last three years with the intent of proposing theoretical
mechanisms explaining the link between suicide and insom-
nia. These mechanisms may then be used as targets for future
investigation of treatment.
Keywords Sleep
.
Depression
.
Suicide
.
Risk factors
.
Insomnia
.
Hopelessness
.
Nightmares
.
Mechanisms
.
Dysfunctional belief about sleep
.
Decision making
.
Serotonin
.
Hyperarousal
.
Circadian rhythm of suicide
.
Psychiatry
Introduction
Millions of Americans suffer from sleep related disorders
such as obstructive sleep apnea, insomnia, and parasomnias,
yet the study of sleep disorders and their long-term conse-
quences is still relatively in its infancy. The recognition of
Sleep Medicine as a legitimate subspecialty of medicine
came upon the wings of a series of developments that include
the establishment of a defined body of specialty-based
knowledge, recognition by the American Medical Associa-
tion, the creation of fellowship training programs approved
by the Accreditation Council for Graduate Medical Educa-
tion (ACG ME), and the creation of board exams sponsored
by the American Board of Medical Specialties (ABMS). In
the course of these developments, the discovery that one
sleep disorder, obstructive sleep apnea (OSA), is associated
with excess mortality [1] elevated sleep problems from the
status of trivial to urgent. In contrast to OSA, the realization
that insomnia is a risk factor for suicide has come only
recently.
Solid evidence has shown that insomnia is a risk factor for
the development of mental illness, with the strongest risk
ratios for depressive illness [2]. The causal mechanism of
this association is not clear. For example, it is unknown
whether insomnia is an independent phenomenon that if
interrupted could forestall the emergence of a mental disor-
der, or whether insomnia is simply the leading edge of an
illness that is already on the way. Investigators are already
examining the former possibility, by way of focusing on
preventing recurrent depressive illness. Success in this line
of investigation would be of immense importance as there
are presently limited numbers of means to prevent or mini-
mize the recurrence of mental disorders of any type.
The importance of these findings has been paralleled by
an accumulating body of evidence that insomnia is a risk
factor for suicidal ideation, suicidal behavior, and suicide
death (which we will collectively refer to here as “suicide”).
Suicidal ideation is defined as a desire to die, or at least an
indifference toward living, that may be accompanied by
specific plans to kill oneself [3, 4]. By extension, suicidal
behavior is a self-harm behavior, or a behavior that is prepa-
ratory to self-harm , and it is intended to lead to the possibility
of death or increase the risk of death. Death by intentional
self-harm would seem to be straightforward, yet sometimes
This article is part of the Topical Collection on Sleep Disorders
W. V. McCall ( *)
Department of Psychiatry and Health Behavior,
Medical College of Georgia, Georgia Regents University,
997 St. Sebastian Way, Augusta, GA 30912, USA
e-mail: wmccall@gru.edu
C. G. Black
Medical College of Georgia, Georgia Regents University,
1120 15th Street, Augusta, GA 30912, USA
e-mail: carblack@gru.edu
Curr Psychiatry Rep (2013) 15:389
DOI 10.1007/s11920-013-0389-9
death is the result of a self-harm act that was originally
intended only to generate a response from others in the
environment. This example would hence not be considered
as suicidal. Suicidal behavior may be attended by simulta-
neous rescue behaviors, i.e., a person cuts their wrists with
the idea of dying yet then goes to lie down in a public place to
see if some one will rescue him/her. This example, however,
would be coded as suicidal behavior [4]. Suicide is complex
and is driven by different mot ivations in different individ-
uals; several competing and potentially conflicting motiva-
tions may operate simultaneously in a given individual.
The evidence base linking insomnia and suicide is both
wide and deep. There are more than 60 separate research
reports that encompass children, adolescents, young adults,
and older persons, and these reports come from the
Americas, Europe, and Asia. A summary of the studies in
adults can be found in Table 1. The reports include popu-
lation studies, clinical sam ples, chart reviews, prospective
case–control cohorts, and clinical trials. The methods of
assessing insomnia vary widely across these studies, with
some studies using validated and standardized measures of
insomnia and other studies only using one-off indicators of
insomnia. Furthermore, some studies reported insomnia as
either present versus absent while other s tudies used di-
mensional measures of insomnia intensity. The measure-
ment of suicide was similarly varied across these studies.
Despite the variability in assessm ent, the basic fi ndings
remain remarkably consistent with relative risks in the
range of 2.0 (Table 1).
Multiple investigations have simultaneously assessed
both “insomnia” and “ nightmares ”, and these studies typ-
ically found that the presence of nightmares was as potent,
or more potent, t han insomnia in predicting suicide [5•, 6].
The term “nightmares” connotes the experience of a dys-
phoric dream during rapid eye movement (REM) sleep,
characterized by a narrative (albeit a disjointed narrative),
high visual impact, and good recall upon awakening. In-
deed, frequent nightmares are reported to increase the risk
of suicidal thoughts by a factor of 1.5–3 and increase the
risk for suicide attempts by a factor of 3–4[7•]. Night-
mares are a common feature of post-traumatic stress disor-
der (PTSD) , a nd perh aps play a role in explaining the
rising rates of suicide in US servicemen returning from
the Global War on Terror [8]. When nightmares as well as
dysfunctional beliefs and attitudes about sleep (DBAS) are
simultaneously considered as mediators between insomnia
and suicide, then the association between insomnia and
suicide disappears [9••]. It is of note, however, that the
correlation between nightmares and suicide may not hold
true in older adults [10], and this may possibly be due in
part because of the sleep changes that occur with increased
age such as a ltered REM sleep patterns and decreased
number of reported nightmares [10].
Recent Reports on the Sleep-Suicide Link
The sheer variety of the sources of data and the convergence
of the findings make a compelling case that the association
between insomnia and suicide is real. Healthy skepticism,
nonetheless, would note that insomnia is a frequent symptom
of depression, and depression is a known risk for suicide. It
could therefore be argued that it is the depression syndrome
rather than the insomnia symptom itself that conveys the
risk. However, meta-analysis shows that the association be-
tween insomnia and suicide still holds even after controlling
for the presence or absence of depressive disorder [11•
] and
after controlling for the intensity of specific symptoms such
as depressed mood and hopelessness [12]. In fact, persistent
insomnia among individuals who lacked depression at base-
line increases the risk of both depression and suicidal
thoughts prospectively across the span of six years [13•].
Nightmares are an additional independent predictor of
suicide [7•]. Nightmares, especially when persistent over
time, can foreshadow suicidal behavior in the form of repeat-
ed suicide attempts among those who had attempted suicide
within the preceding two years [6]. The temporal duration of
insomnia and nightmares, like the intensity of insomnia and
nightmares, is also predictive of suicide. Indeed, unresolved
insomnia and nightmare symptoms were significantly corre-
lated with suicidal ideation among depressed patients who
remitted across a span of four years. Residual nightmares, in
particular, were associated with suicidal ideation with a large
odds ratio of 8.4 [5•]. Furthermore, the overall duration of
insomnia and nightmares increased suicide risk independent-
ly of the current severity of sleep disturbance and depression
[14]. Not only is the duration of the insomnia complaint
relevant as a predictor of suicide, but insomnia is also often
temporally proximal to suicide. In one sample of veteran
suicide deaths, insomni a was documented in nearly half of
the last doctor’s visits preceding suicide death [15].
The associations among insomnia and nightmares and
suicide may or may not be uniform across all ages of pa-
tients. For example, the mechanism explaining the linkage in
children might be different from the linkage in adults. For
this reason, the remainder of this paper will focus on these
relationships in adults.
Insomnia, Hopelessness, and Nightmares—Modifiable
Risk Factors for Suicide
Insomnia, hopelessness, and nightmares can be viewed as
part of the collection of modifiable risk factors for suicide.
Some of the strongest risk factors for suicide cannot be
(easily) modified, and these include age, gender, and race/
ethnicity. On the other hand, there are a larger numbe r of risk
factors that are potentially modifiable which include active
389, Page 2 of 9 Curr Psychiatry Rep (2013) 15:389
Table 1 The relationship between sleep and suicide in adults, by year of publication
Author/year Source of sample Design, N= Sleep disturbance Specified outcome
Barraclough 1975 [64] Suicidal/depressed
outpatients
Cross-sectional, N =192 Insomnia Suicide death
Fawcett 1990 [65] Depressed patients Prospective, N =954 Insomnia Suicide death
Agargun 1997 [66] Depressed patients Cross-sectional, N =41 Insomnia Suicidal thoughts
Agargun 1997 [67] Depressed patients Cross-sectional, N =113 Insomnia Suicidal thoughts
Agargun 1998 [68] Depressed patients Cross-sectional, N =63 Nightmares Suicidal thoughts
Krakow 2000 [69] Female sexual assault
survivors
Cross-sectional, N =153 Sleep breathing & sleep
movement disorders
Suicidal thoughts
Tanskanen 2001 [70] Population survey Prospective, N =36,211 Nightmares Suicide death
Turvey 2002 [71] Population survey Prospective, N =14,456 Insomnia Suicide death
Agargun 2003 [72] Depressed patients Cross-sectional, N =26 REM disturbances Suicidal thoughts
Smith 2004 [73] Chronic pain patients Cross-sectional, N =51 Insomnia Suicidal thoughts
Bernert 2005 [74] Psychiatric outpatients Cross-sectional, N =176 Insomnia & nightmares Suicidal thoughts
Fujino 2005 [75] Population survey Prospective, N =15,597 Insomnia Suicide death
Agargun 2007 [76] Depressed inpatients Cross-sectional, N =149 Insomnia & nightmares Prior suicide attempt
Chellappa 2007 [77] Depressed outpatients Cross-sectional, N =70 Insomnia Suicidal thoughts
Sjostrom 2007 [78] Suicide attempters Cross-sectional, N =165 Insomnia & nightmares Prior suicide attempt
Goodwin 2008 [79] Population survey Cross-sectional, N =8,098 Short sleep Suicidal thoughts & attempts
Bernert 2009 [80] Depressed outpatients Cross-sectional, N =82 Insomnia & nightmares Suicidal thoughts
Sjostrom 2009 [6] Suicide attempters Prospective, N =165 Insomnia & nightmares Repeat suicide attempt
Lee 2010 [81] Population survey Cross-sectional, N =2,054 Insomnia Suicidal thoughts
Li 2010 [82] Outpatient psychiatric clinic Prospective, N =1,231 Insomnia & nightmares Suicide attempts
McCall 2010 [83] Depressed insomniacs Longitudinal, N =60 Insomnia Suicidal thoughts
Nadorff 2010 [84] College survey Cross-sectional, N =583 Insomnia & nightmares Suicidal thoughts
Selvi 2010 [76] Depressed patients Cross-sectional, N =160 Sleep quality, chronotype Suicidal thoughts
Benute 2011 [85] High-risk pregnancy
patients
Cross-sectional, N =268 Insomnia Suicidal thoughts
Bjerkeset 2011 [86] Population survey Prospective, N =74,977 Sleep problems Suicide death
Brower 2011 [87] Population survey Cross-sectional, N =5,692 Insomnia Suicidal thoughts
Carli 2011 [88] Prisoners Cross-sectional, N =1,420 Insomnia Suicidal thoughts
Krakow 2011 [89] Sleep patients Cross-sectional, N =1,584 Insomnia & nightmares Suicidal thoughts
Susanszky 2011 [7•] Community survey Cross-sectional, N =4,642 Insomnia & nightmares Gender differences & suicidal
thoughts & attempts
Klimkiewicz 2012 [90] Substance abusers Cross-sectional, N =304 Insomnia Suicidal thoughts
Li 2012 [5•] Depressed outpatients Prospective, N =371 Insomnia & nightmares Suicidal thoughts
Pigeon 2012 [15] Veteran suicides Chart review, N =381 Insomnia Latency to suicide death
Ribeiro 2012 [12] Suicidal active duty military Cross-sectional and
longitudinal,
N =311
Insomnia Suicidal thoughts & attempts
Suh 2012 [13•] Non-depressed population
survey
Longitudinal, N =1,282 Insomnia Depression & suicide thoughts
or attempts
Bae 2013 [91] General population Cross-sectional, N =1,000 Insomnia Suicidal thoughts
Gunnell 2013 [92] Outpatients Prospective, N =393,983 Insomnia Suicide death
McCall 2013 [
9••] Depressed insomniacs Cross-sectional, N =50 Insomnia, nightmares,
& dysfunctional beliefs
and attitudes about sleep
Suicidal thoughts
Nadorff 2013 [10] Elderly populat ion Cross-sectional, N =81 Insomnia, nightmares Suicidal thoughts
Nadorff 2013 [14] Population survey Cross-sectional, N =972 Insomnia, nightmares Suicidal thoughts & attempts
Suh 2013 [13•] Non-depressed population
survey
Longitudinal, N =1,282 Insomnia Suicidal thoughts & attempts
Adapted from McCall et al. [83] and Norra et al. [93]
Curr Psychiatry Rep (2013) 15:389 Page 3 of 9, 389
symptoms of depression, active alcohol or substance abuse,
social isolation, and some chronic diseases in addition to the
aforementioned processes of hopelessness, insomnia, and
nightmares [16].
Hopelessness is among the strongest psychological risk
factors for suicide, and specific psychological treatments
have been devised in order to address hopeless ideation
[ 17]. It has been shown to a n independent factor that
distinguishes depressed individuals with suicidal ideation
from depressed individuals without suicidal ideation [ 18•],
and it has recently been implicated as a unique contributor
in the contemplative phase of impulsive suicide attempts
[19]. There are also cognitive aspects of chronic insomnia
that have a hopeless “flavor”,suchas“I have little ability
to manage the negative consequences of disturbed sleep”
or “When I sleep poorly on one night, I know it will disturb
my sleep schedule for the whole week”.Thesesortsof
pessimistic cognitions are captured in the Dysfunctional
Beliefs a nd Attitudes about Sleep (DBAS) s cale [20, 21].
Of note, the word “hopeless” never appears in any item of
the scale, although the feeling of hopelessness is certainly
reflected by some of the items.
Psychological Mechanisms
Hopelessness Versus Dysfunctional Beliefs and Attitudes
About Sleep
Based upon the well-described association between hope-
lessness and suicide, it might be expected that some of the
relationship between insomnia and suicide was mediated via
hopelessness. To this end, we examined whether hopeless-
ness was correlated with dysfunctional beliefs and attitudes
about sleep and with the intensity of suicidal ideation in a
sample of 50 persons with depressive disorders of various
types, degrees of severity, and treatment settings. We found
that the DBAS was related to the intensity of suicidal idea-
tion, and insomnia and hopelessness were correlated with
suicide as expected. To our surprise, however, we found that
hopelessness as measured in the Beck Hopelessness Scale
(BHS) was unrelated to the DBAS [9••]. In other words, the
pessimistic cognitions measured by the DBAS represent a
separate cognitive process from the conventional under-
standing of hopelessness. Moreover, both the DBAS score
and the BHS score separately and independently predicted
suicidal ideat ion. Consistent with cross-sect ional evidence,
neither depression nor hopelessness were found to mediate
the link between insomnia and prospective suicidal ideation
and behavior in a study of young adults in the military [12].
These discoveries potentially offer a new target for mitigat-
ing suicide: dysfunctional beliefs and attitudes about sleep.
Sleep, Executive Decision Making, and Suicide
Apart from self-defeating cognitions, insomnia may also
adversely impact cognitive function throu gh impaired deci-
sion making. The role of sleep in memory consolidation has
been well described, as sleep loss is associated with decre-
ments in verbal and visual memory [22]. We recogni ze that
insomnia and sleep deprivation are different problems. In-
somnia and sleep deprivation, nonetheless, share the com-
mon feature of reduced total sleep time, and reduced sleep
time has been associated with impaired decision making
[22]. In particular, insomnia is associated with deficient
problem-solving capacity, especially when involving com-
plex tasks [ 23 •].
Suicide attempters demonstrate problem-solving abnor-
malities that parallel those described in insomniacs. Multiple
studies have shown past suicide attempters exhibit reduced
attention and working memory performance as compared
with depressed non-attempters and non-depressed controls
[24•, 25, 26]. Prior attempters of suicide produced a fewer
number of solutions when faced with an experimental prob-
lem, and those solutions were more passive and less effective
than those created by controls [
27]. Moreover, suicide
attempters may perceive their problem solving skills as in-
adequate, even without any actual problem-solving impair-
ment upon testing [28]. Deficits in problem solving are seen
regardless of the current severity of suicidal thoughts or the
severity of prior suicide attempt [24•, 27], sugges ting that
this is a stable trait. Together these findings raise the possi-
bility that insomnia leads to perceived or documentable
deficiencies in decision making that may lead psychiatrically
ill patients to consider a poorer quality and diminished number
of solutions to their problems. Suicide may perhaps be left as
the only remaining possibility. Under this scenario, treatment
of insomnia might lead to improvements in decision-making
and hence reduced risk of suicide.
Possible Biological and Physiological Mechanisms
Between Insomnia, Nightmares, and Suicide
Serotonin
The insomnia-suicide link may be mediated by serotonergic
mechanisms. The first collection of evidence stems from the
knowledge that serotonin (5-HT) has an important and com-
plex role in the induction and maintenan ce of sleep [29•], and
the complexity of the 5-HT/sleep relationship is exemplified
by a wide variety of 5-HT receptors with different regional
brain distributions [29•]. For this reason, it is impossible to
distill the 5-HT/sleep relationship down to a simple state-
ment such as “5-HT helps you sleep”. For example, admin-
istration of the 5-HT precursor, L-tryptophan, is helpful for
389, Page 4 of 9 Curr Psychiatry Rep (2013) 15:389
sleep [30], and yet facilitation of 5-HT with a serotonin re-
uptake inhibitor can lead to deterioration of sleep [31]. The
possibility that manipulation of sleep could alter the dynam-
ics of 5-HT has been recently reported. In humans, one
in vivo study of cerebral serotonin receptors showed a
9.6 % increase in receptor binding potential after as little as
24 hours of total sleep deprivation [32•]. Furthermore, sleep
deprivation of rodents led to a loss of sensitivity of post-
synaptic 5-HT receptors [33, 34], and this serotonin desensi-
tization was paralleled by a blunted hypothalamic-pituitary-
adrenal (HPA) axis stress reaction in the form of decreased
pituitary cortisol response [33].
Abnormalities in 5-HT function are also seen in suicide
attempters. One of the most replicable biological findings
in suicide is reduced CNS serotonergic (5-HT) function, as
reflected by low levels of serotonin’s main metabolite, 5-
Hydroxyindoleacetic acid (5-HIAA), in the cerebrospinal
fluid (CSF) of suicide victi ms and perpetrators of violence
upon others [35••]. In addition, pre-synaptic serotonin
midbrain transporters were diminished in binding potential
distinctively among those who attempted suicide and/or
suffered suicide death as contrasted to individuals wi th
major depressi on who lacked a past history of suicide
[36, 37]. These findings are consistent with evidence that
chronic alterations of pre-synaptic serotonin a vailability is
intercorrelated with changes in the sensitivity and density
of both pre-synaptic transporters and post-synaptic recep-
tors [38, 39]. Under this scenario, insomnia, and the asso-
ciated reduction in total sleep time, could lead to a loss of
5-HT function, and in turn, increased risk of suicide.
The prefrontal cortex and its control over executive func-
tion are under the influence of the serotonergic system as
well. Inadequate serotonin input to the prefrontal corte x is
known to foster impoverished decision making [40•] and its
ensuing array of aforementioned consequences. Together
these raise the possibility that low 5-HT function is not just
a marker of suicide, but is more so a marker of violent
impulsivity and diminished decision-making skills that low-
er the threshold to suicide.
Hyperarousal
Converging lines of evidence have led to the view that
primary insomnia is a condition of hyperarousal , and its
24-hour span of symptoms is paralleled by a variety of
biological and physiological abnormalities [41]. HPA dys-
function was previously mentioned to be a consequence of
sleep deprivation [33], and cortisol is also a potent biological
marker of suicide risk, particularly in the setting of stress-
related suicide. Stress activates the HPA system and thus
releases a cascade of hormones including but not limited to
corticotrophin-releasing hormone (CRH), adrenocorticotro-
pic hormone (ACTH), and cortisol; these hormones then
augment susceptibility to hyperarousal, REM alterations,
and subsequently suicidal behavior [42••]. Hyperarousal is
typified by inhibition of night time sleep, elevated core body
temperature (especially at night), accelerated electroenceph-
alogram (EEG) rhythms both awake and asleep, and elevated
brain metabolism both awake and asleep [43]. The view of
insomnia as a disorder of physiologic hyperarousal parallels
the view that nightmare symptoms in PTSD are related to
adrenergic overdrive [44]. Thus the link between insomnia
and suicide as well as the link between nightmares and
suicide may share a common feature in hyperarousal and
HPA dysfunction.
Unpleasant mental experiences, however, can presumably
occur outside of REM sleep. These dysphoric non-REM
sleep experiences may be characterized by depressive cog-
nitions occurring during sleep, but without the complex
narratives and high visual impact of a nightmar e. Persons
with de pression are more likely to report depressive mental
content during sleep [45]. Prior reports linking nightmares to
suicide have not clarified whether the link exists for classic
REM sleep-nightmares, or for non-REM sleep depressive
cognition, or both. Clarity is needed as there are treatments
available for PTSD-REM sleep-nightmares that may or may
not have effect in non-REM sleep dysphoric sleep experi-
ences. Specific treatments for PTSD-nightmares include
blocking adrenergic receptors with prazosin [46], suggesting
that adrenergic overdrive is a mechanism behind nightmares
and perhaps other PTSD symptoms such as hypervigilence
[47].
Circadian Rhythm of Suicide
The preceding discussion on insomnia, nightmares, and sui-
cide raises the question of whether a preponderance of sui-
cides occurs at night. To the contrary, suicide between mid-
night and 8 AM is relatively uncom mon, but rises abruptly
between 8 AM and noon [48–51]. How then might sleep
problems contribute to excess suicide during the morning
hours? Much may revolve around what time of the day an
individual naturally feels better. In colloquial terms, some
individuals are naturally “larks” or morning chronotypes,
and others are better described as “night owls” or evening
chronotypes. Neural imaging has even reinforced these con-
cepts by showing diurnal variations in positive-affect related
structures that are in accordance with an individual’s report-
ed chronotype [52]. Chronotype has not been found to be
casual of suicide, per se. However, morningness is associated
with less aggression, is protective against the incidence of
major depression, and provides relief of symptoms among
those who already suffer from major depression regardless of
subjective sleep quality [53••, 54•]. Eveningness, on the
other hand, raises the likelihood of experiencing nightmares,
Curr Psychiatry Rep (2013) 15:389 Page 5 of 9, 389
difficulty falling asleep, poor sleep quality, fewer hours spent
asleep, feeling worse in the morning, and has a well-
established correlation with depression [54•, 55, 56]. The
eveningness chronotype even correlated with a higher degree
of impulsivity and lethality of suici de method in contrast to
morning-type individuals [57]. It is also of interest to note
that new research indicates eveningness to be associated with
a higher cardiovascular disease rate [58, 59 ], and one does
indeed find that other serious medical cris es, such as myo-
cardial infarction [60] and stroke [61], tend to peak during
the same 8 am – 12 pm time frame.
The Way Forward
The understanding of the insomnia-suicide link is in the
earliest stages of development, and therefore most of what
has been presented in this paper is conjectural and intended
only to provide ideas for hypothesis testing. Still, we have
presented a broad array of targets for attack on suicide risk
ranging from distorted cognitions about sleep, to deficient
decision making, to under-performing 5-HT systems, to
hyperarousal. A visual schematic of proposed mechanisms
is presented in Fig. 1. Potential interventions could include
medications, brain stimulation, or psychotherapy depending
upon the model being tested.
There are a series of intermediate steps that could precede
clinical trials of these targets in depressed, suicidal insom-
niacs. In the case of dysfunctional beliefs and attitudes about
sleep (DBAS), it would be useful to establish whether DBAS
can be modified by pharmacolog y or only through cognitive
behavior therapy for insomnia. The finding of deficient
decision-making begs the question as to whether any form
of insomnia treatment, either pharmacologic or psychother-
apeutic, leads to improvements in decision-maki ng. Finally,
the possibility of a link between hyperarousal-insomnia or
hypervigilence-nightmares and suicide suggests that treat-
ments that dampen hyperarousal may lower suicide risk. To
this end there is preliminary evidence that standard benzodi-
azepine agonist hypnotics reduce hypermetabolism in relevant
Fig. 1 The link between
insomnia and suicide: theoretical
mechanisms schematic
389, Page 6 of 9 Curr Psychiatry Rep (2013) 15:389
brain regions of non-depressed insomniacs [ 62]. It is not
known whether a similar effect can be reproduced in de-
pressed insomniacs or with cognitive behavior therapy for
insomnia, and it remains unknown whether these effects
would lead to diminished suicidality.
Conclusion
Global death rates from dysentery and tuberculosis have
fallen in the last 20 years as medicine continues to advance
in the fight against infectious causes of illness, yet suicide is
rising in its importan ce as a global killer, increasing from
14th to 13th place of all causes of mortality [63]. As once
was the case for infection, strategies are lacking for the
prevention of suicide. Recent research has raised the possi-
bility that the treatment of insomnia and nightmares, or
addressing the mechanisms that drive insomnia and night-
mares, may be an avenue for prevention tactics against the
rising threat of suicide.
Acknowledgment This research was supported by National Institutes
of Health grant MH095776-01A1.
Compliance with Ethics Guidelines
Conflict of Interest W. Vaughn McCall has received compensation
from Luitpold Pharmaceuticals for serving as a consultant, has received
royalties from Lippincott Williams & Wilkins for serving as editor for
The Journal of ECT, and has received compensation from CME for
development of educational presentations.
Carmen G. Black declares that she has no conflict of interest.
Human and Animal Rights and Informed Consent This article
does not contain any studies with human or animal subjects performed
by any of the authors.
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