The prevalence and effect of life events in 222 bipolar I and II patients: a prospective, naturalistic 4 year follow-up study

Background: Life events may very well increase the likelihood of affective episodes in bipolar disorder, but prospective data on survival are inconsistent.

Methods: The authors examined the prevalence of negative and goal-attainment life events within 6 months prior to the index episode and after the index episode and their impact on the risk of relapse. Two hundred twenty-two consecutively admitted ICD-10 bipolar I (n=126) and II (n=96) patients were followed-up naturalistically over a period of 4 years.

Results: One-hundred thirty-eight (62.2%) of the patients had at least one life event 6 month before the index episode. Seventy patients (31.5%) experienced one, 48 (21.6%) two, and 20 (9.0%) three (or more) life events. Regarding life events after the index episode, 110 (49.5%) patients had at least one life event. Fifty-four patients (24.3%) experienced one, 31 (14.0%) two, and 25 (11.3%) three (or more) life events. The number of life events was larger in patients with bipolar II disorder than in patients with bipolar I disorder (p=0.004). Using a Cox regression analysis, the risk of a depressive relapse in bipolar I patients was associated with the number of life events after the index episode (p=0.002). This was independent of the quality of the life event.

Limitations: Standardized life event scales, defined dosages of drugs or blood sampling during all visits were not performed.

Conclusions: Our data suggest a high and continuous number of life events prior to affective episodes. Life events after the index episode worsened the course of bipolar I patients with more depressive episodes. This underlines the importance of detection and treatment of emerging life events.