Beyond reactive versus endogenous: Should uncomplicated stress-triggered depression be excluded from major depression diagnosis? A review of the evidence

The concept of an uncomplicated depressive episode was introduced in the DSM-III's "bereavement exclusion" to major depressive disorder (MDD). It represented an attempt to distinguish, among depressive reactions to the loss of a loved one, between those depressions that are normal bereavement-related depressive feelings and those that are depressive disorders. As defined by the DSM, an "uncomplicated" depressive episode is one that satisfies the DSM's symptom and duration diagnostic criteria for MDD but does not cause marked impairment, lacks severe pathosuggestive symptoms such as suicidal ideation, psychotic ideation, intense feelings of worthlessness, and psychomotor retardation, and remits after a relatively brief time. Thus, uncomplicated episodes include only symptoms - such as sadness or low mood, crying, decreased pleasure, difficulty concentrating, loss of interest, fatigue, insomnia, and decreased appetite - that are common in normal distress reactions. Recent studies raise the question whether uncomplicated stress-triggered depressive reactions to any major stressor (not just in reaction to bereavement) form a typologically distinct category different from other MDD and indicative of normal distress. Because the uncomplicated/complicated distinction is a distinction between reactive depressions, it does not resuscitate the repudiated endogenous/reactive distinction. We review the sequence of studies that have been carried out recently exploring the validity of the uncomplicated/ complicated distinction as an indicator of normality/disorder across reactive depressions following all stressors, not just bereavement. Both the concurrent validity (with regard to a large range of validators) and predictive validity (using recurrence as a validator) of the uncomplicated/complicated distinction have been subjected to rigorous tests for the first time, and the results consistently support the validity of the distinction. However, initial studies of concurrent validity suffered from a series of methodological limitations, leaving the answer inconclusive. Recent studies have systematically addressed all of the major objections to the early studies. The results disconfirm the earlier objections and strongly support the validity of the uncomplicated/ complicated distinction as an indicator of normal versus disordered depressive episodes. If the uncomplicated/complicated distinction has validity across stressors, this has important potential prognostic and treatment implications, and might also contribute to a much-needed clarification of the boundary between intense normal sadness and depressive disorder.