Short self-reported sleep duration and suicidal behavior: a cross-sectional study.

BACKGROUND: Prior studies on the association between sleep disturbances and suicidal behavior did not explore whether or not short sleep is a marker of suicide intent, lethality or risk.

DESIGN: Cross-sectional.

PARTICIPANTS: Suicide attempters (SAs) (n=434). Controls included 83 psychiatric inpatients who have never been SAs, and 509 healthy controls.

MEASUREMENTS: Short sleep was defined by self-assessment as ≤ 5 h per day. The MINI and the DSM-IV version of the International Personality Disorder Examination Screening Questionnaire were used to diagnose Axis I and Axis II diagnoses, respectively. Suicide intent and lethality were evaluated through the Beck's Suicidal Intent Scale (SIS) and the Risk-Rescue Rating Scale (RRRS), respectively. Beck's Medical Lethality Scale (BMLS) was administered to assess the degree of medical injury, and the SAD PERSONS mnemonic scale was used to evaluate suicide risk.

STATISTICAL ANALYSES: Chi-square tests and logistic regression analyses explored frequencies of short sleep in 3 samples. Chi-square tests explored whether or not suicide intent, lethality and risk were greater in SAs with short-sleep versus those without short-sleep.

RESULTS: Short sleep was more prevalent in SAs than in psychiatric controls only in males. In female SAs, short sleep was significantly associated with several SIS items and high scores in the SAD PERSONS.

LIMITATIONS: Sleep duration was assessed only by self-report.

CONCLUSIONS: The association between short sleep and suicidal behavior may be partly explained by confounders. Short sleep may be a marker of severity of suicidal behavior among female SAs.