Highly variable sleep schedules predict an elevated risk for suicide independent of depression in actively suicidal young adults, according to a research abstract presented at SLEEP 2010.

Results indicate that a sample of actively suicidal undergraduate students had a delayed mean bedtime of 2:08 AM; restricted total sleep time of 6.3 hours; and highly variable sleep schedules, with time of mean sleep onset varying by 3 hours and time of sleep offset varying by 2.8 hours. However, accounting for baseline depression severity, sleep variability was the only sleep measurement to individually predict increases in suicidal risk at 1 week and 3 weeks. Sleep irregularity also was the only sleep-related variable to predict greater mood lability, which in turn predicted elevated suicidal symptoms.

“To our knowledge, this is the first study to evaluate the unique association between sleep and suicide risk using an objective assessment of sleep and a prospective study design,” said principal investigator Rebecca Bernert, PhD, fellow in the Department of Psychiatry and Behavioral Sciences at Stanford University. “We found that a high degree of irregularity in sleep predicted increases in suicidal symptoms, conferring risk above and beyond the influence of depression. Given that the relationship between sleep disturbances and suicide appears to exist independent of depressed mood, we propose that sleep disturbances may instead confer risk via impaired mood regulation and increased mood lability.”