What do personality tests say about mood disorders? A systematic review

Personality is considered a relevant factor in the development and maintenance of mood disorders. However, the use of different tests based on different theories complicates the generalization of results and the formulation of robust conclusions about this correlation. This study aimed to identify the most commonly used tests for personality assessment in patients with Bipolar Disorder (BD) and Major Depressive Disorder (MDD) and to explore the underlying theories. A systematic review was carried out following the PRISMA guidelines. The search included databases (PubMed/MEDLINE, EMBASE, Web of Science) and gray literature up to August 2024. Of the 2,792 studies, 65 were included, totaling 21,963 patients. The most commonly used tests were the TCI (n = 16), NEO-PI-R (n = 6) and NEO-FFI (n = 6), based respectively on Cloninger's Psychobiological Theory (n = 24) and the Five Factor Model (n = 23). This review indicated that individuals with BD and MDD often show high levels of harm avoidance and neuroticism as well as low levels of conscientiousness, reinforcing the role of tests in identifying personality profiles associated with mood disorders. However, methodological challenges and response bias in self-report tests need to be addressed to improve the reliability of these assessments. Prospero: CRD42023490699.