The relationship between personal aptitudes and affective disorders has been discussed for a long time. There are significant differences between the results of studies comparing temperament and personality traits in individuals with mood disorders and healthy individuals. In a recent study published in the Journal of Affective Disorders, researchers assessed 101 patients with bipolar I disorder (BP-I), 96 patients with bipolar II disorder (BP-II), 123 patients with major depressive disorder (MDD), and 125 healthy individuals (HS) using the Temperament and Personality Inventory (TCI: a dimensional model of the personality-psychopathology link). Specially trained psychiatrists diagnosed and assessed participants’ current and lifetime diagnoses, course, and psychiatric co-morbidity based on a structured diagnostic interview using DSM-IV diagnostic criteria ((A.P.A., 1994). The TCI assesses personality along seven dimensions, including four temperament dimensions: novelty seeking, harm avoidance, reward dependence, and persistence, and three personality dimensions: self- directedness, cooperativeness, and self-transcendence. The analysis revealed that harm avoidance (tendency to respond strongly to aversive stimulus signals, leading to cautious, inhibitory and apprehensive behavior) was higher in BP-II patients and MDD patients, but not in BP-I. Self-transcendence was higher in BP-I patients (self-transcendence: the ability to recall the past and imagine the future in a vivid and concrete way when forming a personal life narrative, as well as the ability to experience unity with nature and to form spiritual values). The analytic model indicated that healthy participants had higher autonomy (the ability to make adjustments and adapt behaviors to the situation in order to reach personal goals) compared to those with MDD or BP-II. There was no significant correlation between the TCI dimension and symptom severity (overall HAM-D and YMRS scores). There was no correlation between CI dimensions and current depressive episode severity. In contrast, there was a positive correlation between harm avoidance and overall burden of lifetime depressive episodes. Limitations of this study were the cross-sectional design and sample heterogeneity. In conclusion, the results of this study support the notion that patients with MDD and BP-II have similar temperament and personality traits, and both are characterized by high harm avoidance and low autonomy. In contrast, BP-I patients showed only high self-transcendence and tended to be normal in terms of harm avoidance or autonomy.