Objective

Sleep disturbances are prevalent, persistent, and impairing features of bipolar disorder. However, the near-term and cumulative impact of the severity and variability of sleep disturbances on symptoms and functioning remains unclear. We examined self-reported daily sleep duration and variability in relation to mood symptoms, medication adherence, cognitive functioning, and concurrent daily affect.

Methods

Forty-one outpatients diagnosed with bipolar disorder were asked to provide daily reports of sleep duration and affect collected via ecological momentary assessment with smartphones over eleven weeks. Measures of depressive and manic symptoms, medication adherence, and cognitive function were collected at baseline and concurrent assessment of affect were collected daily. Analyses examined whether sleep duration or variability were associated with baseline measures and changes in same-day or next-day affect.

Results

Greater sleep duration variability (but not average sleep duration) was associated with greater depressive and manic symptom severity, and lower medication adherence at baseline, and with lower and more variable ratings of positive affect and higher ratings of negative affect. Sleep durations shorter than 7-8 h were associated with lower same-day ratings of positive and higher same-day ratings of negative affect, however this did not extend to next-day affect.

Conclusions

Greater cumulative day-to-day sleep duration variability, but not average sleep duration, was related to more severe mood symptoms, lower self-reported medication adherence and higher levels of negative affect. Bouts of short- or long-duration sleep had transient impact on affect. Day-to-day sleep variability may be important to incorporate into clinical assessment of sleep disturbances in bipolar disorder.

Objectives

Both sleep disruption and impulsivity are important predictors of the course of bipolar disorder (BD). Although sleep disruption has been shown to intensify impulsivity, little research has considered how these two important domains interact within BD. Adolescence is a critical period for the onset of BD, and is often associated with increases in impulsivity and substantial changes in sleep. We tested the hypothesis that disruptions in sleep would increase impulsivity among adolescents, and that this effect would be more pronounced among those with BD.

Methods

Thirteen- to nineteen-year-olds diagnosed with BD-I (n = 33, age [mean ± standard deviation (SD)] 16.2 ± 1.66 years, 54.5% female) and psychiatrically healthy controls (n = 26, age [mean ± SD] 15.5 ± 1.45 years, 55.6% female) reported their past-week bedtime, rise time, and sleep duration, separately for school days and weekends, and completed a self-report questionnaire on impulsivity. Stepwise regression was used to examine the effects of sleep on impulsivity, and the moderation of this effect by BD status.

Results

Adolescents with BD reported significantly higher impulsivity, later and more variable rise time, and more variable time in bed and sleep duration on school days than did controls. Greater change in sleep duration between school days and weekends was associated with significantly more impulsivity among adolescents with BD as compared to controls.

Conclusions

These findings highlight the important effect of sleep on impulsivity among adolescents with BD and add to the growing evidence that establishing sleep routines may be an important therapeutic target for youth with BD.

A growing body of research suggests that the social environment exerts a powerful influence on the course of bipolar depression. This article reviews longitudinal research to suggest that trauma, negative life events, social support deficits, and family difficulties are common and predict a more severe course of depression when present among those diagnosed with bipolar disorder. The triggers of bipolar depression overlap with those documented for unipolar depression, suggesting that many of the treatment targets for unipolar depression may be applicable for bipolar depression.

OBJECTIVE: To evaluate the relative role of psychopathology in the relationship between physical activity and sleep, the present study investigated the day-to-day relationship between physical activity and sleep in individuals without a psychiatric disorder and individuals with bipolar disorder using a longitudinal, naturalistic design. METHOD: Participants in two groups-a healthy group with no psychiatric illness (N=36) and an inter-episode bipolar disorder group (N=32)- were studied over a two-month period. Physical health was assessed by the SF-36. Daily subjective and objective measures of physical activity and sleep were collected. A total of 6,670 physical activity measurements and 6,548 sleep measurements were logged. RESULTS: The bipolar disorder group exhibited poorer physical health on the SF-36 and more sleep disturbance relative to the healthy group. No group differences were found in physical activity, nor in models examining the relationship between physical activity and sleep. Hierarchical linear models indicated that for every standard deviation increase in sleep disturbance (i.e., increased total wake time), there was a three percent decrease in subsequent day physical activity, in both the healthy and bipolar groups. Increased physical activity was associated with improved sleep for participants who reported greater average sleep disturbance. CONCLUSIONS: The results for all participants in the study suggest that reduced physical activity and sleep difficulties may be mutually maintaining processes, particularly for individuals who suffer from poor sleep. Findings also raise the potential importance of targeting physical activity and sleep concurrently in interventions aimed at improving physical and mental health.

Disruptions in activity are core features of mood states in bipolar disorder (BD). This study sought to identify activity patterns that discriminate between mood states in BD. Locomotor activity was collected using actigraphy for six weeks in participants with inter-episode BD type I (n=37) or participants with no lifetime mood disorders (n=39). The 24-hour activity pattern of each participant-day was characterized and within-person differences in activity patterns were examined across mood states. Results show that among participants with BD, depressive days are distinguished from other mood states by an overall lower activity level, and a pattern of later activity onset, a midday elevation of activity, and low evening activity. No distinct within-person activity patterns were found for hypomanic/manic days. Since activity can be monitored non-invasively for extended time periods, activity pattern identification may be leveraged to detect mood states in BD, thereby providing more immediate delivery of care.