Long-term stability of personality traits in a clinical psychiatric sample

Background: The aim of this study was to describe personality traits in psychiatric patients and to investigate whether these traits are stable over 13 years. Methods: A total of 95 individuals who were patients at a psychiatric outpatients' clinic in 2003 completed the Swedish universities Scales of Personality (SSP). Scores from 2003 were compared with SSP scores from 2016. Based on the current score on the comprehensive psychopathological rating scale - self rating for affective disorders (CPRS-S-A), the participants were divided into two groups representing 'good' and 'poor' current mental states, to investigate the effect of current mental state on reports of personality traits. Results: Out of 13 personality traits, 11 showed a significant change in mean T-score over the study interval. The group with lower CPRS-S-A scores showed a significant change in T-score for 10 traits, whereas in the group with higher CPRS-S-A scores only 3 traits showed a significant change. Conclusions: The findings support the theory that personality is changeable over the course of life, also in psychiatric patients. We do not know if persisting psychiatric symptoms halter change or if deviant personality traits cause psychiatric symptoms to continue.