Impulsivity and Sleep and Circadian Rhythm Disturbance as Interactive Risk Factors for Bipolar Disorder Mood Symptom and Episode Onset: Evidence from an Ecological Momentary Assessment (EMA) Study

Abstract

Impulsivity and sleep and circadian rhythm disturbance are two core features of bipolar disorder that are elevated antecedents to bipolar disorder onset and persist even between mood episodes; their pervasive presence in bipolar disorder suggests that they may be particularly relevant to better understanding bipolar disorder etiology, onset, and course. Given considerable research demonstrating bidirectional associations between sleep and circadian rhythm disturbance and impulsivity in healthy individuals, it is surprising that little research has examined how these core features interact to impact bipolar disorder symptomatology, onset, and course. In a sample of late adolescents and young adults (N = 150) at low or high risk for developing bipolar disorder, we employed a naturalistic experiment in the context of an ecological momentary assessment (EMA) design to examine relationships between impulsivity, sleep and circadian rhythm alterations, and mood symptoms in everyday life. Furthermore, we sought to understand how the relationships between sleep and circadian rhythm alterations and mood fluctuation, collected during the EMA study, prospectively predicted mood symptom severity and mood episode onset at a 6-month follow-up. Linear regression, logistic regression, and multi-level modeling (MLM) revealed that higher impulsivity predicted increased mood symptoms during the EMA study, and less total sleep time (measured by actigraphy) predicted increased next-day EMA-assessed mood symptoms. Interaction analyses suggested that dim light melatonin onset time, total sleep time, and sleep onset latency moderated the relationship between impulsivity and mood symptoms (both next-day and at 6-month follow-up). Results are discussed in terms of their contribution to the existing literature. Findings highlight the necessity of multi-method, nuanced examination of the dynamic relationships between impulsivity and sleep and circadian disturbance within bipolar disorder.