Temperament and character profiles of Japanese university students with depressive episodes and ideas of suicide or self-harm: a PHQ-9 screening study.

OBJECTIVE The aim of our study was to reveal the personality traits of individuals with major and other depressive episodes among the young adult population. Furthermore, character traits of individuals with ideas of suicide or self-harm were also investigated in this study. METHODS The subjects of this study were 1421 university students who completed the Patient Health Questionnaire (PHQ-9) and the Temperament and Character Inventory (TCI). The subjects were divided into three separate groups: the major depressive episode group (N = 41), the other depressive episode group (N = 97), and the non-depressive controls (N = 1283). This separation was achieved using the PHQ-9 algorithm diagnosis. We compared the TCI scores using an analysis of variance. Moreover, the Cochran-Armitage trend test was used to determine the diagnosis, ideas of suicide or self-harm, and analysis of character profiles. RESULTS The major depressive episode group had significantly higher HA (P < 0.001), lower RD (P < 0.001), lower SD (P < 0.001), and lower C (P < 0.001) scores than non-depressive controls. The other depressive episode group had significantly higher HA scores (P < 0.001) and lower SD scores (P < 0.001) than non-depressive controls. The Cochran-Armitage trend test revealed that the prevalence of depressive episodes decreased as the character profiles matured (χ(2)(trend) = 57.2, P < 0.0001). The same tendency was observed in individuals who had ideas of suicide or self-harm (χ(2)(trend) = 49.3, P < 0.0001). CONCLUSION High HA and low SD scores were common personality traits among young adults with major depressive episodes. Furthermore, the immaturity of character profiles was clearly associated with depressive episodes and ideas of suicide or self-harm.