Stress sensitivity in women with a history of recurrent versus first-episode major depression.

Approximately 50 % of people who recover from an initial episode of major depressive disorder (MDD) experience a recurrence, and the risk for recurrence increases with each additional episode. Consistent with the stress sensitization model, there is evidence that whereas initial MDD onsets are often preceded by major negative life events, recurrences are often triggered by more minor events. However, it is unclear whether this is due to increased frequency of minor life events, increased reactivity to these events, or both. The current study examined these questions in a community sample of 227 adult women with a history of recurrent MDD (rMDD, n = 77), first-episode MDD (fMDD, n = 38), or no history of MDD (n = 112). Women were assessed at baseline and every six months for two years (5 assessments total). Throughout the follow-up, major and minor life events were assessed using contextual threat interviews and depressive symptoms were assessed using a self-report questionnaire. Regarding event frequency, minor events were more common than major events, and the rMDD group experienced more negative events overall (both major and minor) than the never depressed group but not the fMDD group. Regarding stress reactivity, results of linear mixed modeling revealed that whereas all three groups exhibited similar increases in depressive symptoms following major events, only women in the rMDD group experienced significant increases in depressive symptoms following minor events. These findings show that not only are women with rMDD living in more stressful contexts, but they are also more reactive to minor stressors, increasing risk for future depression.