Five-factor personality traits in patients with schizophrenia and bipolar disorder: a systematic review and meta-analysis.

BACKGROUND

Personality traits play crucial roles in the onset, manifestation, and course of schizophrenia and bipolar disorder (BD). Previous meta-analyses focusing on NEO personality traits in patients with schizophrenia and BD revealed distinct differences in specific personality traits between patients with schizophrenia and healthy controls and between patients with BD and healthy controls. However, direct comparisons of personality profiles between schizophrenia patients and BD patients have been limited, with existing studies often limited by relatively small sample sizes.

METHODS

Two online databases (PubMed and Scopus) were searched systematically to identify relevant articles, including publications up to April 2024. A meta-analysis of five personality traits, namely, neuroticism (N), extraversion (E), openness (O), agreeableness (A), and conscientiousness (C), assessed by the NEO five-factor inventory, was performed in seven cohorts, including our patient samples, consisting of 768 patients with schizophrenia and 555 patients with BD.

RESULTS

There was no significant heterogeneity in the five personality traits among the seven studies (I2 = 0-53.8, P > .05), except for C (I2 = 77.1, P = 5.65 × 10-4). Our meta-analyses revealed significant differences in three personality traits (E, O, and A) between patients with schizophrenia and patients with BD (E: Hedges' g = -0.40, P = 1.34 × 10-11; O: g = -0.22, P = 1.76 × 10-4; and A: g = -0.24, P = 3.73 × 10-5). Patients with schizophrenia had lower scores on E, O, and A than those with BD did. No significant differences in the other two traits, N and C, were observed between the groups (P > .05).

CONCLUSIONS

Our findings suggest that schizophrenia patients and BD patients have distinct personality profiles and that schizophrenia patients have more pronounced personality profiles than BD do, despite their overlapping symptoms and genetic predispositions.