The premorbid personality of patients with different subtypes of an affective illness. Statistical analysis of blind assignment of case history data to clinical diagnoses.

On the basis of case history data, the assumption that there exists an association between the 'manic type' of personality and a predominantly manic course of an affective illness, and between the 'melancholic type' of personality and a unipolar depressive course of the illness was examined. Premorbid data were extracted from 42 case records, 10 of 'unipolar' manic subjects (the ratio of manic to depressive episodes greater than or equal to 4:1), 11 of typical bipolar I patients, 11 of bipolar II patients, and 10 of unipolar endogenous depressives. A rater (J.P.), blind to diagnosis and selection procedure, assigned case notes to personality types. Differences were predicted in terms of personality type between the two unipolar groups, the two bipolar groups and, due to the higher number of cases, also between the combined groups of 'unipolar' manic and bipolar I patients on the one hand, and unipolar depressive and bipolar II patients on the other. According to the Fisher test these predictions were fulfilled. Furthermore, in agreement with our hypotheses on the relationship between premorbid personality and course of the disease, the ratio of assignments to 'manic type' and 'melancholic type' decreased from 'unipolar' mania, to bipolar I and bipolar II disorders, and to unipolar depression.