A study published in 2009 found that stressful events that occurred during or immediately prior to the treatment of depression were associated with poor responses from antidepressant medication. Stressful events did not appear to cause this lack of responsiveness to treatment in psychotherapy, though.
The study was published in the Journal of Consulting and Clinical Psychology and examined 113 depressed outpatients receiving treatment for depression for 16 weeks.
These patients received either cognitive-behavioral therapy, interpersonal psychotherapy, or a variety of antidepressant medications. (Citalopram, fluoxetine, fluvoxamine, sertraline, venlafaxine, or bupropion.)
“Our findings add to a growing body of research suggesting that severe life events experienced during or prior to treatment predict a poor response to treatment. What is unique about the present results, however, is that they extend this area of research by suggesting that this relation may be specific to [antidepressant medication], as these events were not significantly related to response in the psychotherapy conditions,” according to the authors of this research.
The authors believe that cognitive-behavioral therapy and interpersonal psychotherapy may help buffer against the effects of severely stressful life events by providing the patient with skills and techniques to cope with these events.
Those relying on the use of antidepressant medication, on the other hand, do not learn these skills and thus remain vulnerable to severe stressors.
Bulmash. E., Harkness, K.L., Stewart, J.G. & Bagby, R.M. (2009) Personality, stressful life events, and treatment response in major depression. Journal of Consulting and Clinical Psychology, Vol. 77, No. 6: 1067–1077.