Associations between circadian rhythm instability, appraisal style and mood in bipolar disorder.

Background: Internal appraisal styles, in addition to circadian and social rhythm instability, have been implicated in the development of mood experiences in bipolar disorder (BD), yet potential interactions between these variables remain under researched.

Methods: This study used online questionnaires to examine relationships between social and circadian rhythm instability, appraisal style and mood within populations at varying vulnerability for BD.

Results: Participants with BD (n=51), and those at behavioural high-risk (BHR; n=77), exhibited poor sleep quality and a stronger tendency to form internal appraisals of both positive and negative experiences compared to non-clinical controls (n=498) and participants with fibromyalgia (n=80).