BACKGROUND

Classical authors such as Kraepelin, as well as the emerging literature during the past decade, indicate that manic-like signs and symptoms are present to a variable degree in all mood disorders. Current nosography does not differentiate between them and only the number of symptoms or severity is used for classification. This is particularly true for mania and hypomania. This paper will analyze the patterns of manic symptoms in bipolar I (BP-I), bipolar II (BP-II) and major depressive disorders (MDD), to test the hypothesis that mania and hypomania have different profiles, and ascertain which excitatory manic phenomena do occur in unipolar MDD.

METHODS

Six hundred and fifty-two inpatients (158 BP-I, 122 BP-II and 372 MDD) were assessed using the operational criteria for psychotic illness checklist (OPCRIT) [Arch. Gen. Psychiatry 48 (1991) 764] with a lifetime perspective. Manic or hypomanic symptoms were investigated and compared between BP-I, BP-II and MDD.

RESULTS

When compared with BP-II, BP-I disorder had a higher prevalence of reckless activity, distractibility, psychomotor agitation, irritable mood and increased self-esteem. These five symptoms correctly classified 82.8% of BP-I and 80.1% of BP-II patients. One or two manic symptoms were observed in more than 30% of major depressive patients; psychomotor agitation was the most frequent manifestations present in 18% of the MDD group.

LIMITATIONS

We did not control for severity of symptoms, nor for neuroleptic use that could produce akathisia.

CONCLUSIONS

This study suggests that mania and hypomania can be differentiated in their symptom profiles, and highlights the presence of few manic symptoms, particularly psychomotor agitation, in MDD. From the standpoint of number of manic signs and symptoms, controlling for psychomotor agitation did not substantially change the predictive power of the remaining manic symptoms. Given that excitatory manic signs and symptoms are present to a decreasing degree in BP-I, BP-II and MDD, these disorders can be proposed to lie along a dimensional model. Overall, these data are compatible with the concept of a bipolar spectrum, whereby each of the affective subtypes requires specific genetic factors.