The role of affective temperaments in bipolar disorder: The solid role of the cyclothymic, the contentious role of the hyperthymic, and the neglected role of the irritable temperaments.

Background: The aim of the present study is to evaluate the role of individual affective temperaments as clinical predictors of bipolarity in the clinical setting.

Methods: The affective temperaments of 1723 consecutive adult outpatients presenting for various symptoms to a university-based mental health clinical setting were assessed. Patients were administered the Hypomania Checklist-32 and the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego - Auto-questionnaire (TEMPS-A) and were diagnosed by psychiatrists according to the DSM-5 criteria. TEMPS-A scores were studied as both continuous and normalized categorical -scores from a previously established nationwide study on the general population of Lebanon. Simple and multiple binary logistic regressions were done on patients who have any of the DSM-5 defined bipolar types, as a combined group or separately, versus patients without any bipolar diagnosis.

Results: At the multivariable level and taking into account all temperaments, the irritable temperament is a consistent predictor of bipolar I and bipolar II disorders. Cyclothymic temperament also played a strong role in bipolarity but more decisively so in bipolar II and substance-induced bipolarity. The hyperthymic temperament had no role in bipolar I or bipolar II disorder.