The development of major depressive episodes during the course of dysthymic and episodic major depressive disorders: a retrospective examination of life events

Background: The present study examined whether stressful life events are associated with the development of major depressive episodes (MDEs) in a longitudinal, retrospective study of dysthymic and episodic major depressive disorders. Methods: Sixty-seven outpatients with DSM-III-R dysthymia and 38 outpatients with non-chronic major depression were followed up 30-60 months after entry into the study. Follow-up assessments included a modified version of Paykel's (1997) Interview for Recent Life Events (IRLE) and Keller et al.'s (1987) Longitudinal Interval Follow-up Evaluation. Life events were assessed retrospectively in the 6 months before the most recent MDE or in the 6 months before follow-up for patients without a MDE. Results: In dysthymic patients, MDEs were significantly associated with a new life event in the context of an ongoing chronic stressor. In episodic major depressive patients, relapses were associated with new life events regardless of an ongoing chronic stressor Limitations This was retrospective study. It was also a conservative test of the association between life events and MDEs as the follow-up period over which life events were assessed was long, increasing the possibility of forgetting; events occurring less than 1 month before relapse were excluded to avoid confounding the event with the MDE; life events were assessed for a more distant time period for patients who experienced MDEs than those who did not; and an abbreviated version of the IRLE was used which may have failed to identify less severe events. Conclusions: This study suggests that life events may play a role in the onset of MDEs in persons with dysthymic disorder and those with major depressive disorder. Thus, clinicians should monitor dysthymic patients after a stressful life event, particularly if it occurs in the context of a chronic, ongoing stressor. (C) 2000 Elsevier Science B.V. All rights reserved.