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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 encompasses all age ranges. This discovery has invigorated investigation to elucidate the relationship between insomnia and suicide, and over 20 studies reinforcing this association in adults have been published since 2010 alone. This article analyzes relevant research and emphasizes studies published within the last three years with the intent of proposing theoretical mechanisms explaining the link between suicide and insomnia. These mechanisms may then be used as targets for future investigation of treatment.
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The Link Between Suicide and Insomnia: Theoretical
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
Risk factors
Dysfunctional belief about sleep
Decision making
Circadian rhythm of suicide
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
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
C. G. Black
Medical College of Georgia, Georgia Regents University,
1120 15th Street, Augusta, GA 30912, USA
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
casecontrol 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 1.53 and increase the
risk for suicide attempts by a factor of 34[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 doctors 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 NightmaresModifiable
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
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
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
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
N =311
Insomnia Suicidal thoughts & attempts
Suh 2012 [13] Non-depressed population
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
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,suchasI 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
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 serotonins 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.
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
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 [4851]. 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 individuals 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.
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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... Insomnia is not only associated with poor physical and mental quality of life, reduced work productivity, and impaired activity (Bolge et al., 2009), but it is also associated with a risk for independent SI (McCall & Black, 2013;Pigeon et al., 2014). Recently, several studies have examined the association between sleep status and SI (Kim et al., 2013;Owusu et al., 2020). ...
... Even after adjusting for socioeconomic and health factors, insomnia was associated with SI. These results are consistent with previous studies (McCall & Black, 2013;Pigeon et al., 2014). In our analysis of the AIS sub-items, we found that the sub-items "Final awakening earlier than desired" and "Sense of wellbeing during the day" were associated with SI. "Final awakening earlier than desired" describes a con- 8 health psychology report dition in which an individual wakes up during the night or early in the morning and is unable to return to sleep. ...
... There is no conclusive evidence on the mechanism behind the association between insomnia and SI, but several psychological and biological hypotheses have been proposed (McCall & Black, 2013). For example, the psychological hypothesis proposes a model in which dysfunctional beliefs and attitudes about sleep, feelings of hopelessness, and nightmares influence SI. ...
Background: The present study aimed to investigate whether insomnia is associated with suicidal ideation (SI) among Japanese workers by conducting a multi-level analysis with sense of coherence (SOC) as a random effect. Participants and procedure: A cross-sectional survey was conducted among 19,481 workers in Tsukuba, Japan. Data from 7,175 participants aged 20-65 years were included in the analysis. The Athens Insomnia Scale (AIS) was used as the independent variable, and SI over the past year was used as the dependent variable. SOC was measured using the five-point SOC-13 scale, and socioeconomic and health factors were investigated as covariates. Participants were divided into three groups (low, medium, and high) based on their SOC scores. Multilevel logistic regression analysis was performed to calculate odds ratios (OR) and 95% con-fidence intervals (95% CI). Results: In the high-SOC group, only one person had SI. In a multi-level logistic analysis that excluded the high SOC group, insom-nia was found to be associated with SI (OR = 2.26, 95% CI [1.75, 2.93]). Furthermore, the AIS sub-items “Final awakening earlier than desired” (OR = 1.26, 95% CI [1.05, 1.50]) and “Sense of well-being during the day” (OR = 1.63, 95% CI [1.34, 1.99]) were associated with SI. 8.95% or 11% of the variation in the presence or absence of SI was found to be explained by differences between SOC groups. Conclusions: The study highlights that insomnia is associated with SI, and that high SOC may reduce SI even under insomnia. Future longitudinal studies are needed to confirm whether high SOC reduces SI due to insomnia.
... Moreover, intestinal and mucosal layer thinning increases microbiota transmission to the brain and may result in chronic, low-grade inflammation, which is seen in many psychiatric disorders [193]. Furthermore, microbiome composition was examined in the context of reported sleep issues because chronic fatigue has been linked to dysbiosis [194] and insomnia is considered a risk factor for suicidal behaviors [195,196]. Additionally, it has been proven that BDNF in the amygdala and hippocampus, as well as other peripheral and central nervous system Lastly, our analysis reported a positive correlation between HCY and MOODS-SR depressive component as well as with suicidality scores. Our results are in line with previous research, which reported a substantial correlation between HCY and depression [170][171][172][173] but also identified HCY plasma levels as risk factors for the development of depression [174,175]. ...
... Moreover, intestinal and mucosal layer thinning increases microbiota transmission to the brain and may result in chronic, low-grade inflammation, which is seen in many psychiatric disorders [193]. Furthermore, microbiome composition was examined in the context of reported sleep issues because chronic fatigue has been linked to dysbiosis [194] and insomnia is considered a risk factor for suicidal behaviors [195,196]. Additionally, it has been proven that BDNF in the amygdala and hippocampus, as well as other peripheral and central nervous system In this framework, research on microbiota has recently gained increasing importance in the field of psychiatric disorder etiopathogenesis. In fact, a rising body of evidence suggests that gut flora and depression are intimately related, and that gut microorganisms may interact with the brain via peripheral inflammation [188][189][190][191][192]. ...
... Moreover, intestinal and mucosal layer thinning increases microbiota transmission to the brain and may result in chronic, low-grade inflammation, which is seen in many psychiatric disorders [193]. Furthermore, microbiome composition was examined in the context of reported sleep issues because chronic fatigue has been linked to dysbiosis [194] and insomnia is considered a risk factor for suicidal behaviors [195,196]. Additionally, it has been proven that BDNF in the amygdala and hippocampus, as well as other peripheral and central nervous system events, such as cytokine production, short chain fatty acid release, and microglial maturation and activation, are all influenced by microbe-brain interactions [197,198]. ...
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Involving 1 million people a year, suicide represents one of the major topics of psychiatric research. Despite the focus in recent years on neurobiological underpinnings, understanding and predicting suicide remains a challenge. Many sociodemographical risk factors and prognostic markers have been proposed but they have poor predictive accuracy. Biomarkers can provide essential information acting as predictive indicators, providing proof of treatment response and proposing potential targets while offering more assurance than psychological measures. In this framework, the aim of this study is to open the way in this field and evaluate the correlation between blood levels of serotonin, brain derived neurotrophic factor, tryptophan and its metabolites, IL-6 and homocysteine levels and suicidality. Blood samples were taken from 24 adults with autism, their first-degree relatives, and 24 controls. Biochemical parameters were measured with enzyme-linked immunosorbent assays. Suicidality was measured through selected items of the MOODS-SR. Here we confirm the link between suicidality and autism and provide more evidence regarding the association of suicidality with increased homocysteine (0.278) and IL-6 (0.487) levels and decreased tryptophan (−0.132) and kynurenic acid (−0.253) ones. Our results suggest a possible transnosographic association between these biochemical parameters and increased suicide risk.
... Moreover, it was also demonstrated that more SI was significantly associated with higher insomnia severity and directly associated to PLEs positive dimension scores. These outcomes are in agreement with previous studies that discussed the association of SI with both insomnia [72,80,81] and PLES [78,82]. The mediation analysis conducted in this study linked these three variables (PLEs, SI and insomnia) and demonstrated the mediator role of insomnia in this association which extends the findings of previous literature. ...
... Besides, among all sleep problems, insomnia symptoms are the strongest predictors of SI [84]. A broad range of theoretical mechanisms have been proposed to explain the link between insomnia and suicidality (for review, see [80]). Explaining mechanisms include biological and physiological factors (i.e., abnormalities in serotonergic function, hypothalamic-pituitary-adrenal axis dysregulation), chronotype and nightmares [80]. ...
... A broad range of theoretical mechanisms have been proposed to explain the link between insomnia and suicidality (for review, see [80]). Explaining mechanisms include biological and physiological factors (i.e., abnormalities in serotonergic function, hypothalamic-pituitary-adrenal axis dysregulation), chronotype and nightmares [80]. Psychological mechanisms have also been hypothesized, including hopelessness and dysfunctional beliefs about Sleep [80]. ...
Full-text available
Background: Psychotic symptoms reported by healthy individuals in the general population are referred to as psychotic-like experiences (PLEs) and have been proven to increase the risk of suicidal ideation (SI) in these individuals. As it is well established that PLEs and insomnia share a bidirectional association and also that insomnia is linked to SI, we hypothesized that insomnia may represent a mediator underlying the relationship between PLEs and SI. Our aim was to validate this hypothesis among Lebanese young adults. Methods: A total of 3103 young adults (mean age 21.73 ± 3.80 years; 63.6% females) recruited from all Lebanese governorates completed a self-administered online questionnaire. PLEs were assessed using the CAPE-42 scale, SI using the Columbia Suicide Rating Scale, and insomnia using the Insomnia Severity Index). We conducted a mediation analysis using SPSS PROCESS v3.4 model 4 with three pathways. Variables that showed a p<0.25 in the bivariate analysis were entered in the path analysis. Results: A total of 1378 participants (44.4%) had insomnia; 18.8% had SI; 42.5% reported at least one positive PE ‘nearly always’, and 30.5% reported at least one negative PE with this frequency. The results of the mediation analysis showed that insomnia severity partially mediated the association between positive dimension and SI; higher positive dimension was significantly associated with more insomnia severity, which was, in turn, significantly associated with more SI. Finally, more positive dimension was significantly and directly associated with more SI. Conclusion: These preliminary findings might encourage the implementation of new preventive measures to reduce SI among PLEs patients. Treating symptoms of insomnia might help reduce the risk of suicide.
... However, there have also been studies suggesting that insomnia disorder may be a causal factor in the development of depression, anxiety, and alcohol and drug abuse [69,70]. Moreover, data available in the literature suggest several potential mechanisms by which insomnia may increase risk of suicidal ideation and attempts in patients with insomnia, such as reduced cognitive functioning, with impairment in both decision-making and problem-solving ability, as well as nocturnal wakefulness itself [71,72]. ...
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Background: Insomnia disorder is a highly prevalent, significant public health concern associated with substantial and growing health burden. There are limited real-world data assessing the burden of insomnia disorder on daytime functioning and its association with comorbidities. The objective of this study was to leverage large-scale, real-world data to assess the burden of untreated insomnia disorder in terms of daytime impairment and clinical outcomes. Methods: This United States medical claims database study compares patients diagnosed with insomnia disorder but not receiving treatment ('untreated insomnia' cohort) to patients without an insomnia disorder diagnosis and without treatment ('non-insomnia' cohort). International Classification of Disease, Tenth Revision codes were used as a proxy to represent the three symptom domains (Sleepiness, Alert/Cognition, Mood) of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ), a newly developed and validated tool used in clinical studies to assess daytime functioning in insomnia disorder. Chronic Fatigue (R53.83) and Other Fatigue (R53.83), Somnolence (R40.0) and Disorientation (R41.0) were selected as categories representing one or more IDSIQ domains. Clinical outcomes included cardiovascular events, psychiatric disorders, cognitive impairment and metabolic disorders. Results: Approximately 1 million patients were included (untreated insomnia: n = 139,959; non-insomnia: n = 836,975). Compared with the 'non-insomnia' cohort, the 'untreated insomnia' cohort was more likely to experience daytime impairments, with mean differences in occurrences per 100 patient-years for: (a) fatigue, at 27.35 (95% confidence interval [CI] 26.81, 27.77, p < 0.01); (b) dizziness, at 4.66 (95% CI 4.40, 4.90, p < 0.01); (c) somnolence, at 4.18 (95% CI 3.94, 4.43, p < 0.01); and (d) disorientation, at 0.92 (95% CI 0.77, 1.06, p < 0.01). During the 1-year look-back period, patients in the 'untreated insomnia' cohort were also more likely to have been diagnosed with arterial hypertension (40.9% vs. 26.3%), psychiatric comorbidities (40.1% vs. 13.2%), anxiety (29.2% vs. 8.5%), depression (26.1% vs. 8.1%) or obesity (21.3% vs. 11.1%) compared with those in the 'non-insomnia' cohort. Conclusions: This large-scale study confirms the substantial burden of insomnia disorder on patients in a real-world setting, with significant daytime impairment and numerous comorbidities. This reinforces the need for timely insomnia disorder diagnosis and treatments that improve both sleep, as well as daytime functioning.
... In previous studies, college students have shown similar results in approximately half to three quarters of the population by Bahammam et al and Hershner et al. 5,20 Sleep disturbances have also been shown to be a risk factor for mental disorders for decades and are an independent risk factor for suicidal behavior. 21 In our study, 80% of the participants reported good sleep quality. However, only 52% had good sleep quality as per the PSQI index, which shows that the majority of students are not aware of the fact that duration and quality of sleep are not exactly the same; daytime dysfunction, fatigue, and sleepiness also indicate decreased sleep quality. ...
Full-text available
Background: Passionate doctors are required for a better health care system. Increased professional and academic requirements increase risk of developing stress and sleep disruption. This study aims to determine the academic passion, stress and sleep quality among medical students and explore the associations among them, which helps to create awareness to improve the mental and physical health of future doctors. Methods: This cross-sectional study among 649 MBBS students was done at 3 private medical colleges in North Kerala during 2019-2020 using a semi-structured 31-item questionnaire containing 4 sections: socio-demographic information, academic passion, perceived stress, and sleep quality. Data collected in 30 minutes from study participants in campus setting was entered in MS excel and analyzed using SPSS-20. Result: A 61.6% were women and 38.4% were men. 48% had chosen the profession because of parental pressure, relatives and friends. 51% were passionate about the medical profession. 69% of students were under high perceived stress (mean PSI score 33.54±8.71 SD). 48% of students were poor sleepers (mean PSQI score 6.11±3.45). A 15.6% of participants relied on medication for sleep at least once a month. Passion showed a significant association with stress (p<0.001) and sleep (p<0.001). Passionate students had less perceived stress and lower sleep quality. Conclusions: Apart from one's own desire, other factors influenced students to choose MBBS. Only half of the participants were passionate. There is a high prevalence of stress and poor sleep quality among medical students. Passion has an imperative role in one’s life quality.
... [12][13][14] With respect to behavioral health, insomnia occurs in about 70% of behavioral health patients, 15,16 and is associated with poor quality of life, incident cases of major depressive disorder, and suicide. [17][18][19] The American Academy of Sleep Medicine and the American College of Physicians both recommend cognitive behavior therapy for insomnia (CBT-I) as the first-line treatment for insomnia disorder. 20,21 The effect size for CBT-I is moderate, 22 but an estimated 20-47% of patients with insomnia disorder do not complete 23 or respond 1,22,23 to CBT-I. ...
Study objectives: This report gathered data to determine whether daytime assays of the autonomic nervous system (ANS) would differ between persons with nil versus modest insomnia symptoms, and would correlate with the severity of insomnia symptoms in patients. Methods: This report is comprised of two studies. Study 1 conducted pupillary light reflex (PLR) measurements in community volunteers who were not seeking medical care. Study 2 contrasted PLR and heart rate variability (HRV) in a different sample of community volunteers and a comparison sample of adults seeking outpatient care for insomnia and psychiatric problems. All measurements were taken between 3 and 5 PM. Results: In Study 1, volunteers with modest insomnia symptom severity had a more rapid PLR average constriction velocity (ACV) as compared with those with nil symptoms. In Study 2, lower HRV, indicating higher levels of physiologic arousal, generally were in agreement with faster PLR ACV, both of which indicate higher levels of arousal. Insomnia symptom severity was highly correlated with faster ACV in the patient sample. Conclusions: These studies suggest that (1) daytime measurements of the ANS differ between persons with modest versus nil insomnia symptoms, and (2) insomnia symptom severity is highly correlated with the PLR. Daytime measurement of ANS activity might allow for daytime point of care measurement to characterize the level of physiologic arousal to define a hyperarousal subtype of insomnia disorder.
... 36 Several proposed psychological and physiological mechanisms relevant to psychosis-including cognitive distortions and dysfunction, serotonergic dysfunction, hyperarousal, and hypothalamic-pituitary-adrenal axis dysfunction-may mediate the association between insomnia and suicide. [37][38][39] For example, sleep disturbance attributable to positive symptoms may have associated cognitive distortions. 40 Psychosis is also associated with circadian rhythm misalignment in sleep-wake and melatonin cycles, which may contribute to insomnia, and altered circadian clock gene expression. ...
Background and hypothesis: Insomnia occurs frequently in the clinical course of schizophrenia. A growing literature has found associations between insomnia, suicidal ideation and behavior, and psychopathology in schizophrenia. We explored associations between sleep problems, suicidal ideation, and psychopathology in a cohort of patients with first-episode psychosis. Study design: We performed a secondary analysis of data for n = 403 subjects with data from the Recovery After an Initial Schizophrenia Episode study using regression models. Study results: The prevalence of sleep problems and suicidal ideation at baseline was 57% and 15%, respectively. After controlling for potential confounders, in the study baseline sleep problems were associated with increased odds of suicidal ideation with evidence of a dose-dependent relationship (OR = 2.25, 95% CI 1.15-4.41, P = .018). Over 24 months, sleep problems at any time point were associated with an over 3-fold increased odds of concurrent suicidal ideation (OR = 3.21, 95% CI 1.45-7.14, P = .004). Subjects with persistent sleep problems were almost 14 times more likely to endorse suicidal ideation at least once over the study than those without sleep problems (OR = 13.8, 95% CI 6.5-53.4, P < .001). Sleep problems were also a predictor of higher Positive and Negative Syndrome Scale total (β = 0.13-0.22), positive (β = 0.14-0.25), and general (β = 0.16-0.27) subscale scores at baseline and multiple follow-up visits (P < .01 for each). Conclusions: Sleep problems are highly prevalent and associated with suicidal ideation and greater psychopathology in first-episode psychosis. Formal assessment and treatment of insomnia appear relevant to the clinical care of patients with psychosis as a predictor of suicidal ideation and symptom severity.
Longitudinal observational studies have shown a meaningful decrease in suicidal thinking and suicidal behavior after receipt of electroconvulsive therapy (ECT). The antisuicide effect of ECT may be related to success in the global relief of the presenting syndrome such as depressive or psychotic illness. However, it is possible that the antisuicide effect is specific to ECT per se, over and above the relief of the clinical syndrome. Electroconvulsive therapy is associated with many observable neurochemical and physiologic effects, and some of these may plausibly be specifically linked to an antisuicide effect. The phenomenon of physiologic hyperarousal has been named as a candidate mechanism driving the risk for suicide. Hyperarousal is associated with decreased neuropsychological executive function responsible for response inhibition and can lead to impulsive action. The level of arousal within the autonomic nervous system (ANS) can be assayed with the pupillary light reflex, electrodermal activity, or with heart rate variability (HRV). This article summarizes the literature on the effects of ECT on HRV 24 to 72 hours after a course of ECT and finds evidence for increases in HRV, which indicates lower levels of arousal in the ANS. This finding suggests that ECT-related reductions in ANS arousal, presumably with corresponding improvements in response inhibition, may be one mechanism whereby ECT reduces risk for suicide.
Suicidal risk in mothers is a public health priority. Risk factors include biological, psychological and psychosocial factors. Among the biological factors, the role of sleep disturbances as potential contributors to increased suicidal risk during the peripartum period is becoming apparent. To explore this further, we conducted a systematic review following the PRISMA criteria. Currently, 10 studies have examined the role of insomnia and poor sleep quality in suicidal risk during the peripartum period and have involved 807,760 women. The data showed that disturbed sleep and poor sleep quality increase the risk of suicidal ideation in both pregnant women with and without perinatal depression. The results of the meta-analysis indicated that insomnia and poor sleep quality increase the odds of suicidal risk in pregnant women by more than threefold (OR = 3.47; 95% CI: 2.63-4.57). Specifically, the odds ratio (OR) for poor sleep quality was 3.72 (95% CI: 2.58-5.34; p < 0.001), and for insomnia symptoms, after taking into account perinatal depression, was 4.76 (95% CI: 1.83-12.34; p < 0.001). These findings emphasise the importance of assessing and addressing sleep disturbances during the peripartum period to mitigate their adverse effects on peripartum psychopathology and suicidal risk.
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Cognition is central to the experience of insomnia. Although unhelpful thoughts about and around insomnia are a primary treatment target of cognitive behaviour therapy for insomnia, cognitive constructs are termed and conceptualised differently in different theories of insomnia proposed over the past decades. In search of consensus in thinking, the current systematic review identified cognitive factors and processes featured in theoretical models of insomnia and mapped any commonality between models. We systematically searched PsycINFO and PubMed for published theoretical articles on the development, maintenance and remission of insomnia, from inception of databases to February, 2023. A total of 2558 records were identified for title and abstract screening. Of these, 37 were selected for full-text assessment and 12 included for analysis and data synthesis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We identified nine distinguishable models of insomnia published between 1982 and 2023 and extracted 20 cognitive factors and processes featured in these models; 39 if sub-factors were counted. After assigning similarity ratings, we observed a high degree of overlap between constructs despite apparent differences in terminologies and measurement methods. As a result, we highlight shifts in thinking around cognitions associated with insomnia and discuss future directions.
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BACKGROUND: Short sleep duration and decreased sleep quality are emerging risk factors for obesity and its associated morbidities. Chronotype, an attribute that reflects individual preferences in the timing of sleep and other behaviors, is a continuum from morningness to eveningness. The importance of chronotype in relation to obesity is mostly unknown. Evening types tend to have unhealthy eating habits and suffer from psychological problems more frequently than Morning types, thus we hypothesized that eveningness may affect health parameters in a cohort of obese individuals reporting sleeping less than 6.5 hours per night. METHODOLOGY AND PRINCIPAL FINDINGS: BASELINE DATA FROM OBESE (BMI: 38.5±6.4 kg/m(2)) and short sleeping (5.8±0.8 h/night by actigraphy) participants (n = 119) of the Sleep Extension Study were analyzed (, identifier NCT00261898). Assessments included the Horne and Ostberg Morningness-Eveningness questionnaire, a three-day dietary intake diary, a 14-day sleep diary, 14 days of actigraphy, and measurements of sleep apnea. Twenty-four hour urinary free cortisol, 24 h urinary norepinephrine and epinephrine levels, morning plasma ACTH and serum cortisol, fasting glucose and insulin, and lipid parameters were determined. Eveningness was associated with eating later in the day on both working and non-working days. Progression towards eveningness was associated with an increase in BMI, resting heart rate, food portion size, and a decrease in the number of eating occasions and HDL-cholesterol. Evening types had overtly higher 24 h urinary epinephrine and morning plasma ACTH levels, and higher morning resting heart rate than Morning types. In addition, Evening types more often had sleep apnea, independent of BMI or neck circumference. CONCLUSIONS: Eveningness was associated with eating later and a tendency towards fewer and larger meals and lower HDL-cholesterol levels. In addition, Evening types had more sleep apnea and higher stress hormones. Thus, eveningness in obese, chronically sleep-deprived individuals compounds the cardiovascular risk associated with obesity.
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Suicidality and suicide has been associated with many risk factors, while recent clinical and epidemiological studies increasingly point to a potential link between sleep loss or sleep disturbances and suicidality. This review on studies of sleep disturbances associated with suicidality, i.e., suicidal ideation, suicide attempt and completed suicide suggests a frequent association especially with insomnia and nightmares but also hypersomnia and sleep panic attacks. In suicidal insomniacs with comorbid psychiatric disorders, there is some evidence for an even independent predictive nature of sleep problems for suicidality. Considerations on the shared neurobiology, risk assessment and treatment options complement the overview. Thus, sleep disturbances may qualify as an individual treatable target of personalised medicine in the clinical routine as well as in suicide prevention programmes. A more detailed assessment of sleep problems and identification of specific risk domains in primary or secondary prevention of suicidality seem to be a future area of high importance.
As part of the National Institute of Mental Health Epidemiologic Catchment Area study, 7954 respondents were questioned at baseline and 1 year later about sleep complaints and psychiatric symptoms using the Diagnostic Interview Schedule. Of this community sample, 10.2% and 3.2% noted insomnia and hypersomnia, respectively, at the first interview. Forty percent of those with insomnia and 46.5% of those with hypersomnia had a psychiatric disorder compared with 16.4% of those with no sleep complaints. The risk of developing new major depression was much higher in those who had insomnia at both interviews compared with those without insomnia (odds ratio, 39.8; 95% confidence interval, 19.8 to 80.0). The risk of developing new major depression was much less for those who had insomnia that had resolved by the second visit (odds ratio, 1.6; 95% confidence interval, 0.5 to 5.3). Further research is needed to determine if early recognition and treatment of sleep disturbances can prevent future psychiatric disorders. (JAMA. 1989;262:1479-1484)