A FACTOR-ANALYSIS OF THE SIGNS AND SYMPTOMS OF MANIA

Background: No adequate factor analyses of signs and symptoms of mania have been reported. From limited past reports, the view has arisen th at 2 main symptom clusters (euphoric-grandiose and paranoid-destructiv e) occur in patients with mania, along with so-called core symptoms of psychomotor pressure. In this view, dysphoric mania is associated wit h paranoid-destructive symptoms and with psychosis. Methods: We rated 237 patients with DSM-III-R-defined bipolar disorder, manic (n=204) or mixed (n=33), on 15 classic features of mania and 5 features related to dysphoric mood. Principal components factor analysis was applied to the ratings. Results: Five clearly interpretable and clinically relev ant factors were identified. The first and strongest factor represente d dysphoria in mania, with strong positive loadings for depressed mood , lability, guilt, anxiety, and suicidal thoughts and behaviors and a strong negative loading for euphoric mood. Factors 2 through 5 represe nted psychomotor acceleration, psychosis, increased hedonic function, and irritable aggression, respectively. The distribution of weighted s cores on factor 1 was bimodal, whereas the corresponding distributions of factors 2 through 5 were unimodal. Contrary to all past reports, n o general factor denoting overall severity of mania was found. Factors previously proposed by Beigel and Murphy were not confirmed. Conclusi ons: Five independent factors representing dysphoric mood, psychomotor pressure, psychosis, increased hedonic function, and irritable aggres sion were identified. The conventional view of symptom factors in mani a was not confirmed. Dysphoric features are statistically salient in p atients with mania, and the bimodal distribution of the dysphoria fact or is consistent with the possibility that mixed bipolar disorder is a distinct state.