Insomnia, Nightmares Risk Factors for Suicidal Behavior

Batya Swift Yasgur, MA, LSW

June 29, 2017

Sleep disturbances are predictive of acute suicidal ideation in young adults, independently of depression severity, and can be regarded as acute warning signs, new research shows.

A large-scale study conducted by investigators at Stanford University School of Medicine in California showed that self-reported insomnia and nightmares and actigraphically assessed sleep variability emerged as acute warning signs of suicidal ideation.

"Sleep is a barometer of our well-being and directly impacts how we feel the next day," lead investigator Rebecca Bernert, PhD, told Medscape Medical News.

"We believe that poor sleep may fail to provide an emotional respite during times of distress, impacting how we regulate our mood and thereby lowering the threshold for suicidal behaviors," she said.

A team of researchers observed almost 5000 young adults aged 18 to 23 years, including 50 who had been prescreened on the basis of a history of suicide attempt and recent suicidal ideation, at three time points during a 21-day period.

The study was published online June 28 in the Journal of Clinical Psychiatry.

Top Warning Sign

Young adulthood is characterized by a "shared prevalence of sleep disturbance and suicide risk," the authors note. Sleep disturbances have been recognized as "among the top warning signs of suicide." Additionally, "preliminary research suggest that they may confer risk for suicidal behaviors," the authors write.

However, previous studies that investigated this association were flawed by "methodological limitations," including reliance on subjective complaints, such as self-reported insomnia, fatigue, and poor subjective sleep quality as risk factors for suicidality.

"Although surveyed sleep complaints had been previously evaluated as a risk factor, a study had yet to investigate disturbed sleep as an acute indicator of risk, using an objective index of sleep among young adults," Dr Bernert commented.

For their study, the researchers employed a longitudinal design and utilized validated symptom measures and an acute time frame to "evaluate whether this relationship emerges using objective and subjective sleep measures."

To provide ongoing assessment, they used sleep actigraphy in which the actigraphy device was worn for a week. Actigraphy has been previously validated as an accurate way to distinguish sleep-wake patterns. In addition, they explored whether "intraindividual mood variation" was associated with suicidal ideation and sleep parameters.

The researchers recruited participants (n = 4897) from a university undergraduate research pool who on screening had been found to be at high risk for suicide.

Participants had to be aged 18 years or older and had a history of either one or more past suicide attempts and recent suicidal ideation (≤6 months), or no past history of suicide attempt but a history of current (≤1 month) and recent (≤6 months) suicidal ideation.

The researchers measured suicide risk on the basis of the Beck Scale for Suicidal Ideation (BSS) and the Pierce Suicidal Intent Scale (SIS).

Sleep actigraphy provided an objective measurement of sleep. Derived variables included sleep-onset latency, total sleep time, wake after sleep onset, sleep efficiency, and sleep variability (standard deviations of daily sleep onsets and sleep offsets).

The researchers included additional variables, such as average bedtime and wake time, the amount of time in bed (regardless of time asleep), and nap and sleep interval frequency. The actigraphy sleep data were computed for a 7-day period for each participant.

In addition to this objective measure, the researchers administered subjective sleep instruments, including the Insomnia Severity Index (ISI), which they describe as a "gold standard insomnia instrument." They also used the Disturbing Dreams and Nightmare Severity Index (DDNSI) and the Visual Analog Scale mood variability (VAS-MV).

The covariates of depression and alcohol-related problems and dependence were assessed with the Beck Depression Inventory-II (BDI-II) and the Alcohol Use Disorders Identification Test (AUDIT), respectively.

Sleep Variability, Mood Changes

Participants were assessed at baseline, 7 days, and 21 days. The researchers used hierarchical multiple regression analyses to test hypotheses. They assessed causal risk and temporal ordering by longitudinally assessing symptom relationships, with adjustment for baseline symptoms in each model.

The researchers found "common" alcohol-related problems and "moderate to severe" depressive symptoms among participants. Mean BSS scores pointed to moderate suicidal symptoms, with the maximum scores in the severe range for suicidal ideation.

There was high adherence with the keeping of sleep diaries and the use of actigraphy. Shift work as well as extended wakefulness seemed to be associated with greater sleep variability, determined on the basis of mean actigraphy metrics and their interconnections.

Of the 50 participants, 96% (n = 48) endorsed a history of suicide attempts and exhibited objectively disturbed sleep parameters, as measured by actigraphy.

Subjective measures showed that 78% (n = 39) endorsed clinically significant insomnia, and 36% (n = 18) endorsed clinically significant nightmares. The researchers found that variability in sleep timing, insomnia, and nightmares predicted increases in suicidal ideation (P < .05).

Even when controlling for baseline suicidal and depressive symptoms, the researchers found that actigraphic and subjective sleep parameters predicted suicidal ideation residual change scores at both time points of follow-up (P < .001).

Post hoc analyses revealed that greater sleep variability and less variability in total sleep time were significant predictors of changes in 7-day BSS change measures (P ≤ .02). Significant intercorrelations were observed for sleep variability at 7-day ISI (r = 0.35; P = .02) and DDNSI (r = 0.02; P = .04) scores.

In a test of competing risk factors, sleep variability was found to be more predictive of suicidal ideation than depressive symptoms in the longitudinal prediction of suicidal ideation across time points (P < .05).

Sleep variability and VAS-MV significantly predicted BSS symptoms change at 7-day follow-up, with sleep variability and VAS-MV accounting for "more unique variance in prediction of BSS symptoms change, compared to BDI-II," the researchers report.

"Insomnia, nightmares, and sleep variability were highly correlated, and variability in mood served as an additional warning sign of suicidal symptoms, alongside sleep disturbances," said Dr Bernert.

"Insomnia and nightmares beget more variability in the timing at which we are able to fall asleep on subsequent nights, which speaks to the way in which insomnia develops," she added.

Opportunity for Suicide Prevention

Commenting on the study for Medscape Medical News, Maria Wong, PhD, professor, Department of Psychology, Idaho State University, in Pocatello, called it "a very valuable study, linking objectively measure sleep parameters to changes in suicide symptoms.

"Previous research, including my own, showed the self-report of sleep problems predicted suicide ideation and attempts. This study showed that objectively reported sleep variability prospectively predicted suicide symptoms," said Dr Wong, who was not involved in the study.

One weakness of the study is that the sample size was small and therefore the study had "low statistical power," she pointed out. "Moreover, only sleep variability predicted the outcome."

Nevertheless, the study has immediately applicable take-home messages. "Clinicians should assess insomnia symptoms, variability in sleep time, and other sleep parameters when they work with suicidal patients," she said. "They should discuss sleep habits with these patients and, if necessary, prescribe medications to help patients sleep better."

Additionally, "psychiatrists should ask patients with sleep disturbances whether they have suicidal thoughts."

Dr Bernert observed that "treatments tested for suicidal behaviors are alarmingly scarce in comparison with need and remain mismatched to the acute nature of a suicidal crisis."

In comparison to other risk factors for suicide, "disturbed sleep is modifiable, nonstigmatizing, and highly treatable using brief, fast-acting interventions," she pointed out.

"In this way, we believe the study of sleep may represent an important opportunity for intervention and the prevention of suicide, which is preventable but remains a silent killer and global disease burden, underscoring the new for new treatment and novel strategies for intervention."

She recommended the American Academy of Sleep Medicine and the National Sleep Foundation as "excellent resources" to assist clinicians who treat patients with sleep disturbances.

Anyone who is experiencing symptoms of suicide can receive help by calling the National Suicide Prevention Lifeline at (800) 873-TALK or by texting the Crisis Text Line (text HOME to 741741). All helplines offer free, confidential support 24 hours a day.

The research was supported by the John Simon Guggenheim Foundation and the National Institutes of Health. The Department of Psychiatry and Behavioral Sciences, Stanford University, also supported the work. The authors have disclosed no relevant financial relationships.

J Clin Psychiatry. Published online June 28, 2017. Abstract


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.