Objective: This study aimed to explore how prevalent agitated "unipolar" major depression is, whether it belongs to the bipolar spectrum, and whether it differs from nonagitated "unipolar" major depression with respect to course and outcome.
Method: The study was conducted from January 1, 1978, to December 31, 1996. From 361 patients with major depressive disorder, the authors selected those fulfilling Research Diagnostic Criteria for agitated depression. These 94 patients were compared to 94 randomly recruited patients with nonagitated major depressive disorder regarding demographic and historical features, the clinical characteristics of the index episode, the percentage of time spent in an affective episode during a prospective observation period, and the 5-year outcome. Patients with agitated major depressive disorder who had at least 2 manic/hypomanic symptoms in their index episode were compared to the other patients with agitated major depressive disorder with respect to the same variables.
Results: Patients with agitated major depressive disorder were more likely to receive antipsychotics during their index episode and spent a higher proportion of time in an affective episode during the observation period compared with patients with nonagitated major depressive disorder. The presence of at least 2 manic/hypomanic symptoms in the index episode was associated with a higher rate of family history of bipolar I disorder, a higher score for suicidal thoughts during the episode, a longer duration of the episode, and a higher affective morbidity during the observation period.
Conclusion: The diagnosis of agitated major depressive disorder is not uncommon and has significant therapeutic and prognostic implications. The subgroup of patients with at least 2 manic/hypomanic symptoms may suffer from a mixed state and/or belong to the bipolar spectrum.