Psychopathological characteristics of bipolar and unipolar depression - potential indicators of bipolarity.

BACKGROUND Establishing whether a depressive episode is part of a unipolar or bipolar disorder is essential for treatment planning. Over recent years, a growing number of publications have discussed psychopathological characteristics that might serve as indicators of bipolarity in patients with a history of depression dominated by unipolar symptoms. Our primary aim was to verify the adequacy of these indicators in contributing to a precise diagnosis in everyday clinical practice. SUBJECTS AND METHODS We investigated 104 patients diagnosed with major depressive episode at the time of examination. 52 patients had major depressive disorder and 52 patients had bipolar disorder. The patients were then assessed for the presence of potential bipolarity indicators: psychomotor slowing, self-view (self-blaming, feelings of worthlessness), hypersomnia, increased appetite, leaden paralysis/loss of physical energy, weight increase, interpersonal sensitivity, and early morning insomnia, using the Inventory of Depressive Symptomatology. We analysed the correlations between these indicators and the presence of unipolar or bipolar affective disorder. RESULTS Psychomotor slowing, self-blaming/feelings of worthlessness, increased appetite, leaden paralysis/loss of physical energy, and weight increase were significantly more frequent in bipolar depression than in unipolar depression (p<0.05). Early morning insomnia was significantly more frequent in unipolar depression (p<0.05). There was no statistically significant correlation between hypersomnia or interpersonal sensitivity and either of the affective disorders. CONCLUSIONS It would be worthwhile identifying the relative importance of clinical indicators for probable BP in large-scale prospective studies. These would contribute to the better diagnostic assessment of major depressive episodes and therapeutic decision-making.