Sleep disturbance as a proximal predictor of suicidal intent in recently hospitalized attempters

Insomnia and short self-reported sleep duration are associated with suicidality, adjusting for concurrent depression. Yet, it is unknown whether they correlate with attempters' suicidal intent and the lethality of suicidal acts. This cross-sectional study in hospitalized suicide attempters aimed to investigate whether temporally proximal self-reported sleep disturbance predicts suicidal intent or exerts mediatory effects.

Attempters were retrospectively assessed for insomnia severity (Athens Insomnia Scale [AIS]) and average night sleep duration (ANSD) for 2 weeks preceding attempt. The effects of insomnia or ANSD on suicidal intent (Beck's Suicide Intent Scale [BSIS]) were explored in multiple regressions. Mediatory effects were investigated in structural equation models (SEMs).

A total of 127 adults (59.8% females) were interviewed within two weeks post-suicide attempt. Major psychiatric diagnoses included affective, psychotic, and alcohol-related disorders. Of the participants, 38.6% had current major depression (MDE). A total of 62.2% reported insomnia (AIS ≥ 6); 42.5% reported short ANSD (≤5 hours). BSIS was predicted by AIS (p = 0.034), short ANSD (p = 0.015), or insomnia with short ANSD (p = 0.006). In SEMs, indirect effects of current MDE, affective disorder, and alcohol-related disorder diagnoses on BSIS via AIS tested significant; both AIS and short ANSD partially mediated the effect of age on BSIS.

Insomnia, short ANSD, and, in particular, insomnia with short ANSD proximally predicted suicidal intent in recent attempters. The effects of current depression and affective and alcohol-related disorder diagnoses on suicidal intent were partially mediated by insomnia; both insomnia and short ANSD partially mediated the effect of age on suicidal intent. Therefore, management of sleep disturbance in at-risk subjects is important, as it may reduce unfavorable outcomes of suicidal acts.