Chronic and nonchronic unipolar depression. The differential role of environmental stressors and resources.

There appear to be strong variations in the association between psychosocial factors and the onset and course of depressive disorders. To explore a possible correlate of such variation, we consider whether the role of social-environmental factors may differ between patients with a recurrence of unipolar depression and a recent history of prior treatment (termed chronic patients), patients with unipolar depression but without a recent prior treatment episode (termed nonchronic patients), and a demographically matched group of nondepressed controls. Both chronic and nonchronic patients experienced more stressors and reported fewer social resources than nondepressed controls, but the two patient groups did not differ on these factors. However, correlational analyses indicated that stressors and social resources were significantly related to functioning among nondepressed controls and nonchronic patients, but not among chronic patients. These findings support the value of specifying subgroups of individuals for whom depression is most strongly related to psychosocial factors.