Chance discovery of multiple personality disorder in a depressed patient by amobarbital interview.

Although the diagnosis of multiple personality disorder (MPD) has been receiving renewed interest in the literature, it presents a number of clinical problems and challenges. A case study is reported in which this diagnosis was uncovered by chance during an amobarbital interview on a psychotically depressed young male patient. The patient had previously been only minimally responsive to pharmacotherapy for a major depressive episode with mood-congruent psychotic features. When the multiple personality disorder was diagnosed, treatment emphasis shifted toward psychotherapeutic modalities with marked clinical improvement. Several unique aspects of the case, including diagnostic methodology, results of serial dexamethasone suppression tests, and psychosomatic symptomatology, are discussed as well as the implications of this case within a larger clinical context.