Issues in Treatment-Resistant Depression.

Major depressive disorder is a debilitating disease that imposes significant social and economicburdens not only on patients but also on society. Although various treatment options are available,treatment-resistant depression is common. Determining the exact prevalence of treatment-resistantdepression is difficult because definitions vary, as do definitions of antidepressant response. Operationaldefinitions of antidepressant response, nonresponse, partial response, and remission will be discussedin this article. Pharmacotherapy options for patients with treatment-resistant depression includeaugmentation, combination, and switching therapies; however, data from controlled clinicaltrials supporting these therapies are limited. Electroconvulsive therapy and psychotherapy offer additionaltreatment strategies. New nonpharmacologic therapies are under investigation. Remission is thegoal of treatment.