The role of stress in the onset of depressive disorders. A controlled study in a Spanish clinical sample.

Abstract

We conducted the present study to evaluate the impact of stressful events on the onset of depressive disorders in a Spanish clinical sample, compared to a control group matched for age, sex, civil status and social class. We compared our results with those of other studies carried out with samples that were both clinically and culturally similar to ours. Fifty depressed patients that were diagnosed with a depressive episode in the 6 months prior to the interview and 50 healthy controls were included in the study. Both groups were compared on the "Life Events and Difficulties Schedule" (LEDS). Of the depressive patients, 68 % compared to only 18 % of the control individuals experienced at least one provoking agent in the 12 months prior to the onset of the symptoms. The risk of developing a depressive disorder was 9.7 % greater in subjects exposed to such provoking agents. Chronic difficulties are equally important to the genesis of depressive disorders as severe life events. No significant differences were seen between the two diagnostic subgroups of depressed patients in the accumulation of severe events, major difficulties or provoking agents. The results support the view that stress is a major factor in the aetiology of depressive disorders. The amount of stress suffered by the patients, however, was less than that found in our healthy sample. Important issues about the model of interaction between stress and depression are discussed.