Rest‐Activity Rhythms and Suicidal Ideation in Pediatric Bipolar Disorder

ABSTRACT Introduction Risk for suicide is disproportionately elevated among youth with bipolar spectrum disorder (BD), which is characterized by recurrent mood episodes and significant shifts in sleep and circadian rhythm. Disruptions in circadian rhythm, such as 24‐h rest‐activity patterns, are a relevant risk factor for SI, yet understudied in BD youth. The present cross‐sectional study examined the associations between actigraphy‐derived rest‐activity rhythms (RARs) and self‐reported suicidal ideation (SI) severity in a sample of 54 BD youth (aged 12–18 years). Method Participants completed daily wrist actigraphy (M days = 18.89, range: 6 to 29 days) and non‐parametric RAR measures were derived for analyses. At the same time, participants provided self‐report data on depressive symptoms and SI severity (number of days between actigraphy start and questionnaire completion: M days = −7.74, SD = 13.33, range: −46 to 28 days). Primary analyses examined associations between RAR variables and SI severity, controlling for several key covariates including age, BD subtype, psychotropic medication use, and depressive symptoms. Results Results revealed that greater interdaily stability and higher average activity levels during wake were associated with lower SI severity. These results remained significant even when controlling for the aforementioned covariates. Conclusion Results indicated that greater and more consistent activity levels within and across days are associated with lower suicide risk. Findings suggest that RARs are relevant for suicide risk detection and intervention for BD youth.