Bipolar disorder is a severe mental illness that manifests itself in recurrent (hypo-) manic and depressive episodes affecting approximately 1.3% of the Dutch population. The Dutch multidisciplinary guideline advices self-management of bipolar disorder next to pharmaceutical- and psychological treatment to prevent recurrent episodes. Self-management of bipolar disorder entails a bundle of non-pharmaceutical interventions, such as mood monitoring, rapid response on early warning signs, recurrence prevention, and social rhythm therapy. Standing on their own, these self-management interventions for bipolar disorders seem to be effective. However, outcomes vary across the population and it is unknown how self-management education for bipolar disorders works. This study examined the underlying mechanisms of educational self-management interventions for bipolar disorders.