Research has consistently documented the significance of severe life events for the onset and course of major depression. However, no research has been done on whether social and clinical characteristics differ in depressed primary care attendees who have experienced stressful life events compared to those who have not.

We investigated whether social and clinical characteristics differ in depressed primary care attendees who have experienced stressful life events compared to depressed primary care attendees who have not.

We undertook a prospective cohort study involving 5,442 consecutive primary care attendees with evaluations at baseline and at 6 months. Patients aged 18-75 years were recruited in six Spanish provinces between October 2005 and February 2006. The incidence of major depression was assessed at 6 months with the Depression Section of the Composite International Diagnostic Interview (CIDI). Stressful life events were measured with the List of Threatening Experiences (LTE).

3,804 (70%) were interviewed at 6 months of follow-up. Among 200 attendees with a first episode of major depression, 24.5% had experienced no stressful life events, 30.5% had suffered one, 20.5% had experienced two and 24% had suffered three or more in the 6 months prior to the onset of depression. Depressed primary care attendees who had experienced three or more stressful life events differed from depressed patients with no stressful life events in the following variables: economic difficulties, dissatisfaction with unpaid work, relational variables, psychiatric co-morbidity and family history.

Stress-related major depression differs from non-stress-related depression in primary care.