Exploring the margins of the bipolar spectrum: temperamental features of the typus melancholicus

Background: Both the melancholic type of personality (TM) and the concept of temperament offer promising insights for the phenotypic characterization of mood-spectrum vulnerability. This research challenges the theoretical hiatus between the two psychopathological paradigms - the phenomenological and the neo-Kraepelinian - by means of an empirically-based approach. Method: Temperamental features were assessed through the Semi-structured Affective Temperament Interview (TEMPS-1) in an outpatient population of 116 clinically stable, euthymic subjects who suffered from a DSM IV major depressive disorder, previously enrolled for a study on the characteristics of major/unipolar depressive episode. The sample was subsequently evaluated and dichotomized according to the Criteria for Typus Melancholicus (CTM). Results: The TM subjects exhibited statistically significant differences in the temperamental profile as compared to non-TMs (NTM). A specific association between TM and hyperthymic temperament (HT) was confirmed by binary logistic regression analysis, suggesting that the phenomenological distinction TM vs. NTM is supported by different predisposing Kraepelinian "fundamental states". Limitation and conclusions: Although it is uncertain whether the findings would generalize outside the Italian culture, they nonetheless delineate a strong aggregation between TM and hyperthymic temperament, indicating that (1) an integrative neo-Kraepelinian/phenomenological cooperative model is warranted to tap the complexity of the phenotypic diathesis for mood-disorders, and (2) the hyperthymic- melancholic type of personality rests on the margins of the bipolar spectrum. The main limitation of this study is that it enrolled a selected outpatient volunteer sample. A large scale study in general population is needed to confirm the hypothesis of a strong link between TM and HT and to shed light on the causes and meanings of this association. (c) 2006 Elsevier B.V.. All rights reserved.