Relationship between the core features of Tellenbach's Typus Melancholicus and unipolar depressive disorders: a cross-sectional study

Purpose: One of the most consistent models investigating the relationship between premorbid personality and depression was described by Tellenbach. According to this model, concern with orderliness, conscientiousness, hyper/hetereonomia and intolerance of ambiguity are the core features of Typus Melancholicus (TM). Previous studies showed a relationship between unipolar depression and TM. The primary hypothesis of this study was that patients affected by unipolar depressive disorders bare more of TM-related features of concern with orderliness and conscientiousness than healthy subjects. Methods: In this single center cross-sectional study we recruited 74 patients affected by unipolar depressive disorders according to DSM-5 criteria and 60 healthy controls. In order to assess the presence of TM's orderliness and conscientiousness we adopted the factors of Kasahara's Inventory for the Melancholic Type Personality (KIMTP) named "harmony in personal relationships" and "social norms". Stress-Related Vulnerability Scale (SVS) was administered to explore the relationship between measures of TM and perceived stress. Results: Independent sample t test disclosed significantly higher scores on KIMTP "harmony in personal relationships" (orderliness) but not on "social norms" (conscientiousness) in the clinical sample (p<0.001) compared to the non-clinical sample. Pearson's correlation disclosed a significant positive correlation between stress scores and KIMTP'S "harmony in personal relationships" subscale. Discussion and conclusions: KIMTP's "harmony in personal relationships" (orderliness) was higher in patients with unipolar depression than in non-clinical subjects, and positively associated with perceived stress, while KIMTP's "social norms" (conscientiousness) was (i) similarly represented across the two groups, and (ii) not correlated with perceived stress. This raises the possibility that, among the core features of TM, concern with orderliness can be considered as a relevant and potentially premorbid personality factor in relation to unipolar depressive disorders.