Personality traits and change in depression status at 18 months: Findings from a British Psychiatric Morbidity Survey

Background: Depression is a common mental disorder, yet it shows low remission rates. The available evidence on personality traits as factors associated with the course of depression has common methodological limitations. Identifying personality traits linked with depression can improve understanding of the course of illness. Therefore, we aimed to investigate personality traits that are associated with the course of depression over 18 months. Methods: longitudinal data of 2366 Adult Psychiatric Morbidity Survey respondents were analysed. Assessments were applied at two-time points (baseline) and follow-up (about 18 months later). We assessed the total score on the screening questionnaire from the Structured Clinical Interview (SCID-II) for the dependent, obsessive- compulsive, and borderline personalities. Depression was measured using the revised Clinical Interview Schedule (CIS-R) version. Results: An increase of one score on the borderline personality scale at baseline increased the odds of experiencing persistent depression by 1.50 times (OR = 1.50, 95 % CI [1.22-1.86]), depression onset by 1.30 times (OR = 1.30, 95 % CI [1.14-1.50]), and recovery by 1.52 times (OR = 1.52, 95 % CI [1.35-1.70]), comparing to no depression group. Elevated scores of dependent personality traits significantly predicted depression persistence (OR = 1.95, 95 % CI [1.52-2.49]). An increase of one score on the obsessive-compulsive personality scale increases the odds of depression onset by 1.21 times (OR = 1.21, 95 % CI [1.04-1.39]). Limitations: The APMS survey defined depression statuses in a limited sense, which may affect the generalisability of these results. Conclusion: The present study confirms previous findings and contributes evidence suggesting that personality dysfunctions worsen depression outcomes.