One model of bipolar disorder proposes that “changes in daily social rhythms or schedules lead to disruption of circadian rhythms and, in turn, onset of bipolar mood episodes” (see references). Social rhythm therapy works by helping each person find and work to best maintain regular patterns in their life such as work, school, sleep, and recreation. It also helps people identify and solve challenges or issues that may interfere with maintaining regular patterns.
Ehlers, C. L., Frank, E. & Kupfer, D. J. Social Zeitgebers and Biological Rhythms: A Unified Approach to Understanding the Etiology of Depression. Arch. Gen. Psychiatry 45, 948–952 (1988).
Alloy, L. B., Boland, E. M., Ng, T. H., Whitehouse, W. G. & Abramson, L. Y. Low social rhythm regularity predicts first onset of bipolar spectrum disorders among at-risk individuals with reward hypersensitivity. J. Abnorm. Psychol. 124, 944–952 (2015). (Note: reward hypersensitivity means that people may overreact or overvalue positive changes, information, or things)