Life-event specificity: bipolar disorder compared with unipolar depression

Background Little is known about the impact of different types of stressful events (for example divorce v. bereavement) on unipolar depression compared with bipolar disorder. Inconsistencies exist concerning the association between independent events (beyond an individual's control, such as bereavement) and bipolar disorder. Aims To examine the role of specific, independent and dependent events in mood disorders. Method Life-event information was collected from 512 people with bipolar disorder, 1448 people with unipolar depression and over 600 controls. Results Various events were associated with unipolar depression and bipolar disorder, but some event specificity was detected. For example, financial crisis was more strongly related to bipolar disorder rather than unipolar depression. Independent events were only related to unipolar depression and not bipolar disorder. Conclusions The events that were linked to bipolar disorder and unipolar depression were similar. Independent events were not associated with bipolar episodes, suggesting that life stress may be a consequence of, rather than a trigger for, bipolar episodes.