Longitudinal associations of temperament and character with paranoid ideation: A population-based study

The aim of this study was to examine (a) the associations of temperament and character dimensions with paranoid ideation over a 15-year follow-up in the general population (b) the associations of explosive temperament and organized character profiles with paranoid ideation. 2137 subjects of the Young Finns Study completed the Temperament and Character Inventory and the Paranoid Ideation Scale of the Symptom Checklist-90 Revised in 1997, 2001, and 2012. Temperament dimensions of high novelty seeking, high harm avoidance, low reward dependence and explosive temperament profile were associated with the development of higher paranoid ideation. Regarding character, high self-directedness, high cooperativeness, and low self-transcendence and organized character profile were associated with lower paranoid ideation. These associations sustained after controlling for age, gender, and socioeconomic factors. However, the associations between temperament and paranoia mostly disappeared after taking character into account. Our study supported the hypothesis that personality dimensions contribute to the development of paranoid ideation. Temperament and character might combine a variety of single previously found risk factors into a more comprehensive framework for the developmental etiology of paranoia. Our findings provide evidence for psychotherapeutic interventions that support the self-regulation of temperamental vulnerabilities by internalizing mature concepts about the self and social relationships.