Mild emotional stress or sadness can reactivate depressive thinking in people who have recovered from a bout of depression. This may increase the risk of a relapse. Researchers from the University of Toronto, Canada, found that remission from depression can be a period of marked sensitivity to emotional stress as well as an increased risk of relapse. The researchers analysed 301 adults recovering from a major depressive disorder and examined whether mood-linked changes in thinking predicted relapse. In the first phase of the study, the patients were treated with antidepressant medication or cognitive behaviour therapy. In phase 2, regular clinical assessments were conducted for 18 months in the 99 patients who achieved clinical remission. During the second phase, the subjects underwent a sad mood provocation. They were asked to recall a time in their lives when they felt sad, and at the same time the researchers made them listen to the orchestral introduction to Russia Under the Mongolian Yoke by Prokofiev, played at slow speed. Previous studies have found this to bring on an unhappy mood. Those who received antidepressant medication showed a greater tendency to have depressive thoughts after mood provocation, as compared to patients who underwent cognitive behaviour therapy. The magnitude of the mood-linked response predicted relapse during the 18 months, regardless of the type of previous treatment. The findings suggest that even a mild negative mood, when experienced by someone with a history of depression, can re-instate some of the cognitive features observed in depression itself. Further understanding of factors predisposing to a relapse in recovered patients may help to shorten the potentially lifelong course of depression.
Archives of General Psychiatry,
July 2006