Inaccuracy between subjective reports and objective measures of sleep duration and clinical correlates in bipolar disorder

Abstract

Background: Sleep disturbances are common in bipolar disorder (BD) and are often assessed by self-report at clinic visits over the course of BD treatment. Self-report may be subject to recall bias based upon current mood/affect states. This study sought to identify the degree of inaccuracy between subjective and objective measures of sleep duration in those with and without BD, and to assess the demographic and clinical correlates of this inaccuracy. Methods: Thirty-one individuals with BD and 54 healthy control (HC) participants reported on the number of hours slept a night over the past month and subsequently completed up to 14 days/nights of wrist actigraphy which provided an objective measure of sleep duration. We compared the subjective rating to the average of all nights of objective sleep duration, and correlated the magnitude of inaccuracy with demographic and clinical characteristics in the BD and HC groups. Results: On average, both BD and HC groups overestimated their sleep, and there were no differences in inaccuracy between groups. In the BD group, greater inaccuracy was associated with lower functioning, even after controlling individually for objective and subjective sleep measures. Limitations: Cross-sectional study, only focus on sleep duration, and less severe bipolar symptoms of sample. Conclusions: Inaccuracy in reports of sleep duration was associated with lower functioning among BD patients. Better identifying discrepancies in reports of sleep duration in clinical practice could help in more efficient monitoring and management of BD symptoms.