Objective. - The presence of at least five dimensions in mania has recently been established. This study extends previous findings by comparing the dimensions of pure vs. mixed mania.

Materials and method. - One hundred and three inpatients with bipolar I disorder, manic or mixed (DSM IV), were assessed with SCID-I, YMRS and HDRS-21. The five-factor solution found after applying factorial analysis with Varimax rotation was compared between manic and mixed patients.

Results. - There were differences between pure mania and mixed states on factor 1 (depression) and factor 3 (hedonism). There was a tendency to present higher values on factor 5 (activation) in the pure manic group. No differences were found in factor 2 (dysphoria) and factor 4 (psychosis).

Discussion. - Hedonism and activation dimensions are present to a lesser degree in mixed states. Although the principal difference between mixed and pure bipolar disorder is the existence of depressive symptoms, the depressive dimension is strongly present in patients with pure mania.

Conclusions. - There is need to search for core depressive symptoms in all patients suffering from mania and to evaluate their outcome in clinical trials.