Associations between circadian rhythm instability, appraisal style and mood in bipolar disorder
© 2016 Elsevier B.V. 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). Participants with BD also exhibited a stronger tendency to adopt an internal, negative appraisal style compared to individuals at BHR. Sleep disturbance and internal appraisal styles were significantly associated with low mood in BD. Limitations Sleep quality and social rhythm stability were assessed using self-report measures only, which may differ from objective measures. Causal relationships between constructs could not be examined due to the cross-sectional design. Conclusions The findings suggest the importance of attending to internal appraisal styles and sleep quality when working therapeutically with individuals diagnosed with BD. Potential differences in the effect of appraisal style at the state and trait level warrant further exploration.