The profile and familiality of personality traits in mood disorder families

ObjectivePersonality traits have impacts on individuals' response to stress and mood expression. The current study aimed to investigate the profile of personality traits in patients with bipolar disorders and major depressive disorder (MDD). Familial aggregation of personality traits in mood disorder families was also evaluated.MethodsWe recruited 260 clinical patients of MDD (92), bipolar disorder-I and II (BP-I = 111, BP-II = 57), 190 first-degree relatives, and 180 controls. Four personality traits were assessed using the Eysenck and Tridimensional Personality Questionnaires, including Extraversion (E), Neuroticism (N), Harm Avoidance (HA), and Novelty Seeking (NS). The magnitude of familiality of personality traits in mood disorder families was evaluated by mixed models and intra-class correlation coefficients (ICC).ResultsPatients with mood disorders had lower E, and higher N, HA and NS than controls. Unaffected relatives were not differed from controls in the four personality traits. BP-I had higher E, NS and lower N, HA than MDD patients (p < 0.01). The scale N further distinguished BP-I from BP-II (p = 0.02) with lower N among BP-I patients. There exhibited moderate familiality in E (ICC = 0.184-0.239) and HA (ICC = 0.355) in bipolar disorder families.LimitationPersonality traits were accessed cross-sectionally without quantitatively controlled severity of mood symptoms.ConclusionDifferent patterns of personality traits distinguish patients from unaffected individuals as well as separate diagnoses of mood disorders, indicating the usage of more comprehensive evaluation of personality traits in clinical settings. Familiality of extraversion and harm avoidance in bipolar disorder families provides insights for further investigating correlates of comorbid behavioral problems in bipolar disorders.