Severe melancholic depression is more vulnerable than non-melancholic depression to minor precipitating life events.

BACKGROUND The present study examines the moderating role of global depression severity on the relation of melancholic versus non-melancholic depression to severe and non-severe levels of stress. METHOD A community sample of 50 women with unipolar major depressive disorder, of which 54% met Research Diagnostic Criteria for melancholic depression, were interviewed regarding stressful life events experienced prior to onset. Events were coded as severe or non-severe based on the rigorous Bedford College contextual rating system. RESULTS Greater severity of depression was related to a higher likelihood of a severely stressful event prior to onset only for women with non-melancholic major depression. By contrast, greater severity of depression was related to a higher likelihood of a non-severe, more minor, stressful event prior to onset only for women with melancholic major depression. LIMITATIONS The present study was limited by its use of a female volunteer sample, which might not be entirely representative of the population of individuals with major depression. In addition, the study employed a cross-sectional design, which limits conclusions relating to the causal relation of stress to melancholic versus non-melancholic depression. CONCLUSIONS Far from being autonomous of stress, individuals with severe melancholic depression may be especially sensitive to stress, such that their episodes are influenced by more minor stressors than those of individuals with non-melancholic depression.