Major depressive disorder: a study based on revised-reinforcement sensitivity theory of personality

Background:  Study of personality can help to explanation of pathology in mental disorders. The aim of this study was to examine major depressive disorder (MDD) based on revised- reinforcement sensitivity theory (r-RST). Materials and Methods: Forty-five patients with MDD along with 45 healthy individuals as a control group participated in the present study. Following the informed consent form, Structured Clinical Interview (SCID-I), General Intelligence Test (SGIT), Jackson's 5-factor questionnaire for assessing personality, and Beck Depression Inventory (BDI-II) were administered to the two groups. Data were analyzed using Chi-square, independent t-test, analyses of variance (ANOVA), and multiple analyses of variance (MANOVA). Results: MANOVA results showed a significant difference between MDD and control groups in the items of Jackson's 5-items questionnaire. The MDD group score in r-BAS (P<0.001, h2=0.242) was lower than that of the control group but was higher in r-BIS (P<0.001, h2=0.367), Fight (P<0.001, h2=0.245), Flight (P<0.001, h2=0.068) and Freeze (P<0.001, h2=0.081). Conclusion: Depression is significantly related to behavioral inhibition system but not related to behavior activation system. A more knowledge of r-RST can help in the diagnosis, aberration and continuation of common mental disorders. The results of this study can help in understanding the pathology associated with the personality of patients with MDD.