Bipolar disorder (BD) confers elevated suicide risk and associates with misaligned circadian rhythm. Real-time monitoring of objectively measured sleep is a novel approach to detect and prevent suicidal behavior. We aimed at understanding associations between subjective insomnia and actigraphy data with severity of suicidal ideation in BDs.
This prospective cohort study comprised 76 outpatients with a BD aged 18 to 65 inclusively. Main measures included 10 consecutive days of wrist actigraphy; the Athens Insomnia Scale (AIS); the Montgomery–Åsberg Depression Rating Scale (MADRS); the Quick Inventory of Depressive Symptoms-16, self-rating (QIDS-SR-16); and the Columbia Suicide Severity Rating Scale. Diagnoses, medications, and suicide attempts were obtained from chart review.
Suicidal ideation correlated moderately with subjective insomnia (AIS with QIDS-SR-16 item 12 ρ =0.26, P = 0.03; MADRS item 10 ρ = 0.33, P = 0.003). Graphical sleep patterns showed that suicidal patients were enriched among the most fragmented sleep patterns, and this was confirmed by correlations of suicidal ideation with actigraphy data at 2 visits. Patients with lifetime suicide attempts (n = 8) had more varied objective sleep (a higher standard deviation of center of daily inactivity [0.64 vs. 0.26, P = 0.01], consolidation of daily inactivity [0.18 vs. 0.10, P = <0.001], sleep offset [3.02 hours vs. 1.90 hours, P = <0.001], and total sleep [105 vs. 69 minutes, P = 0.02], and a lower consolidation of daily inactivity [0.65 vs. 0.79, P = 0.03]).
Subjective insomnia, a nonstigmatized symptom, can complement suicidality screens. Longer follow-ups and larger samples are warranted to understand whether real-time sleep monitoring predicts suicidal ideation in patient subgroups or individually.