Suicide remains the second leading cause of death in young adults, but factors that may predict increased suicide risk have not been characterized, wrote Rebecca C. Cox, PhD, of the University of Colorado Boulder, and colleagues.
“Sleep disturbance is a promising modifiable risk factor for acute changes in suicide risk,” they noted. “Previous research has found multiple aspects of sleep disturbance are linked to elevated SI, including insomnia symptoms, both short and long sleep duration, nocturnal wakefulness, and nightmares.”
However, data on the impact of nightly sleep disturbance on suicide risk are limited, the researchers said. They hypothesized that use of ecological momentary assessment (EMA) to assess daily variability in sleep might offer more insight into the relationship between various components of sleep disturbance and changes in suicide risk.
In a study published in Psychiatry Research , the investigators recruited 102 young adults aged 18-35 years who had a history of suicidal behavior; 74.5% were female, 64.7% were White. Participants completed seven semi-random surveys per day for between wake and sleep schedules over 21 days. Each survey asked participants to report on whether they had experienced suicidal ideation (SI) since the last survey. The researchers examined within-person and between-person sleep variables including bedtime, sleep onset latency, sleep onset, number of awakenings, wake after sleep onset, sleep duration, sleep timing, sleep quality, and nightmares.
Overall, nightmares had a significant, positive effect on passive SI at both within- and between-person levels, but no significant effect on active SI. Sleep latency showed a significant, positive effect on passive and active SI at the between-person level, meaning that “participants who took longer to fall asleep on average were more likely to experience passive and active SI during the sampling period,” the researchers noted.
In addition, days following nights of more time awake between sleep onset and offset were days with increased likelihood of passive and active SI. Similarly, days following nights of worse sleep quality than normally reported for an individual were days with increased likelihood of passive and active SI. Sleep timing and duration had no significant effects on SI at the within- or between-person level.
“Notably, tests of reverse models found no relation between daily passive or active SI and any component of the subsequent night’s sleep, suggesting a unidirectional relation between sleep disturbance and subsequent SI,” the researchers wrote in their discussion. If future research replicates the study findings, the results could support the inclusion of sleep difficulties on standard risk assessments as a way to identify risk for SI and initiate prevention approaches, they said.
The findings were limited by several factors including the potential for unmeasured variables impacting the associations between sleep and SI, the researchers noted. Other limitations included the lack of data on more severe levels of SI such as planning and intent, and on suicidal behaviors such as preparatory behaviors, aborted attempts, and actual attempts. The findings also may not generalize to other age groups such as children, adolescents, or older adults, they said.
More research is needed to determine which sleep disturbance components are acute risk factors for which suicide-related outcomes, the researchers said. However, the study is the first to provide evidence for daily sleep disturbances as a near-term predictor of SI in young adults, they concluded.
The study was supported in part by the National Institutes of Health. The researchers had no financial conflicts to disclose.