First author, Lewis L. Judd, M.D., said the end of major depressive episodes is currently defined as eight weeks with “no more than minimal” residual symptoms. The definition includes two levels of depressive symptom resolution: Asymptomatic recovery (no depressive symptoms) and residual symptom resolution (some mild continued symptoms). The researchers compared the two levels in regards to their likeliness of resulting in future depressive episodes.
Data was analyzed from 322 patients with major depressive episodes who were followed for up to 31 years. 62.1 percent of patients recovered asymptomatically. Dr. Judd added that this group remained depression-episode free for 4.2 times longer than those who still had residual symptoms.
Residual symptoms were three times as likely to increase the return of major depressive episodes within one year. The residual symptom group also experienced greater depressive illness burden in the following 10 to 20 years – they had greater difficulties with household chores and personal relationships.
Dr. Judd suggests that treatment for depressive symptoms should continue until all symptoms are completely resolved. He added, “If you treat a major depressive episode until there are no remaining symptoms, the individual is likely to enter a stable state of wellness and be free of depression for months or even years. As long as they have any residual symptoms, they are still ill and at high risk for relapse.”
Dr. Judd says the findings suggest, for the first time, the end of major depressive episodes in terms of symptoms and necessary duration. For the asymptomatic period necessary to define the end of major depressive episodes, the researchers suggest four consecutive weeks defines recovery.
The findings were published in Journal of Clinical Psychiatry.