Sleep problems and suicidal behaviors in college students

Abstract

Using a large sample of college students, objectives were to examine (1) the overlap between poor sleep and suicide risk status, (2) whether poor sleep was associated with suicide behaviors above and beyond depression, (3) whether sleep problems and depression interacted to predict increased suicidal behaviors or risk, and (4) which specific components of sleep were uniquely associated with suicidal behaviors. Participants were 1700 college students (ages 18-29 years; 65% female) from two universities who completed measures assessing sleep, depressive symptoms, and suicidal behaviors (Suicidal Behaviors Questionnaire–Revised [SBQ-R], a composite measure including ideation, past attempt, disclosure to others, and future likelihood of suicide that includes a cutoff for determining participants with suicide risk). Approximately one-quarter (24%) of participants were classified with suicide risk. Four-fifths (82.7%) of participants classified with suicide risk also met cutoff criteria for sleep problems; conversely, almost one-third (31.3%) of the participants classified with sleep problems were also classified with suicide risk. Total sleep problems remained significantly associated with suicidal behaviors above and beyond depressive symptoms, though sleep and depression did not interact to predict suicidal behaviors or risk. When considered together and controlling for sex, the odds of being classified with suicide risk were 6.54 times greater for participants with elevated depressive symptoms and 2.70 times greater for participants with sleep problems. Analyses examining specific sleep domains found shorter sleep duration, having bad dreams, feeling too cold while sleeping, and sleep medication use to each be independently associated with suicidal behaviors. Findings add to a growing body of literature linking sleep and suicide in college students.

Introduction

Evidence from cross-sectional, longitudinal, case control, and psychological autopsy studies support a link between sleep problems and suicidal behaviors (Bernert et al., 2015, Pigeon et al., 2012, Woznica et al., 2015). However, even though sleep problems are common in college students (Becker et al., 2018, Lund et al., 2010, Orzech et al., 2011) and suicide is a leading cause of death in young adults (Centers for Disease Control and Prevention, 2015, Schwartz, 2006), few studies have examined sleep in relation to suicidal behaviors in college student samples. In fact, a systematic review published in 2015 (Bernert et al., 2015) found only three studies examining sleep and suicide risk in college students (Cukrowicz et al., 2006, Nadorff et al., 2011, Nadorff et al., 2013), with four additional studies published after the systematic review was conducted (Bernert et al., 2017, Bozzay et al., 2016, Nadorff et al., 2014, Supartini et al., 2016) and one additional study not included in the systematic review (Vail-Smith et al., 2009). As described next, these studies have made important contributions to our understanding of sleep in relation to suicidal behaviors in college students, yet also point to the need for additional research in this area.

Five of the studies to date examined insomnia symptoms (Bozzay et al., 2016) or both insomnia symptoms and nightmares in relation to suicide ideation/behaviors (Cukrowicz et al., 2006, Nadorff et al., 2011, Nadorff et al., 2014, Nadorff et al., 2013). In a sample of 438 female college students from a single university, Bozzay et al. (2016) found insomnia symptoms were significantly associated with suicidal ideation after controlling for depression. In a sample of 222 college students, Cukrowicz et al. (2006) found nightmares, but not insomnia symptoms, to be significantly associated with suicidal ideation when depressive symptoms were controlled. This differential finding was replicated by Nadorff et al. (2011) in a larger study of 583 students. However, in a separate sample of 673 college students, Nadorff et al. (2013) found both insomnia symptoms and nightmare duration to be independently associated with suicide behaviors, above and beyond internalizing symptoms. A third study by Nadorff and colleagues reported mixed evidence for whether nightmares alone or both insomnia symptoms and nightmares were associated with increased suicide risk/attempts in two samples of college students (Ns = 747 and 604) (Nadorff et al., 2014). Studies to date have largely focused on whether sleep problems are independently associated with suicidal behaviors, with most studies examining whether sleep problems are incrementally associated with suicidal behaviors above and beyond depression Extant studies in non-college student samples have not found support for this sleep interacting with depression in predicting suicidal behaviors (Ferentinos et al., 2016, Gelaye et al., 2016), though we are not aware of any studies that have tested this possibility in college students. Considered together, the handful of existing studies have laid the groundwork for examining sleep and suicide in college students, yet these studies were unable to examine other sleep domains outside of insomnia symptoms and nightmares that may also be associated with suicidal behaviors. This is consistent with the broader literature examining the link between sleep and suicide, which has primarily focused on insomnia symptoms (broadly defined) and nightmares (McCall and Black, 2013, Woznica et al., 2015). Even among these studies, “few studies [have] attempted to identify associations between specific insomnia symptoms and suicide risk” (Woznica et al., 2015, p. 41), making this a clear research priority.

Two studies have examined sleep in relation to suicidal ideation among college students beyond insomnia symptoms and nightmares. One study of 859 college students found that students who reported suicidal ideation reported significantly worse overall sleep quality than students who did not report suicidal ideation (Vail-Smith et al., 2009). More recently, Supartini et al. (2016) used the Pittsburgh Sleep Quality Index (PSQI) (Buysse et al., 1989) in a sample of 1992 Japanese college students and found that students with suicidal ideation were more likely to be classified with poor sleep than students without suicidal ideation. Poor overall sleep quality remained associated with suicidal ideation when accounting for depressive symptoms and other covariates (e.g., age, sex). Although important, this study did not examine specific sleep domains on the PSQI (e.g., sleep duration, sleep quality) and used a single yes/no item to assess suicidal ideation. Our study aims to build on these findings by using the PSQI in a sample of United States college students.

The present study adds to the limited empirical evidence examining the link between sleep and suicide risk in college students. Using validated measures of both sleep and suicidal behaviors in a large sample of college students, we examined (1) the proportion of students meeting cutoff criteria for suicide risk who also met cutoff criteria for poor sleep, (2) whether poor sleep was associated with suicide behaviors above and beyond depression (with all variables examined both continuously and categorically), and (3) whether the association between sleep problems and suicidal behaviors was moderated by depression. We hypothesized that the majority of students meeting the cutoff for suicide risk would also be classified with poor sleep and that poor sleep would remain associated with suicidal behaviors/risk after controlling for depression, though we did not expect sleep and depression to interact in predicting suicidal behaviors/risk. Finally, since most studies have examined insomnia specifically as opposed to more specific sleep domains, we explored (4) whether specific aspects of sleep and/or daytime sleepiness were uniquely associated with suicidal behaviors.