Personality traits and night eating syndrome in women with bulimia nervosa and binge eating disorder

PURPOSE: Previous research suggests that eating disorders may be associated with certain personality profiles; however, there is limited research investigating associations with night eating syndrome (NES). This research suggests harm avoidance personality trait is higher in NES individuals than in the general population, however, evidence of associations with other personality traits is inconsistent. To understand which personality traits are associated with NES symptoms, the current study aimed to improve understanding of the relationship between NES symptoms and a range of personality traits, addressing limitations in the earlier literature in this area by controlling for common confounders. METHODS: Baseline data were analysed from an outpatient psychotherapy trial for 111 women with bulimia nervosa or binge eating disorder. Pre-treatment measures of personality traits (measured with the Temperament and character inventory—revised) and NES symptoms (measured with the Night eating questionnaire) were used. Regression analyses tested associations between these variables, adjusting for potential confounders, including age and ethnicity. RESULTS: Low cooperativeness scores were associated with greater NES symptoms in the multivariable model (mean difference: − 0.10, 95% confidence intervals: − 0.20 to − 0.01, p = 0.033). There was weak evidence of associations between both high harm avoidance and low self-directedness personality traits and greater NES symptoms. CONCLUSIONS: This study adds to the limited research measuring associations between a range of personality traits and NES, addressing limitations of previous research. Weak evidence for an association between high harm avoidance and low self-directedness and increased NES symptoms was found. A novel association was found between low cooperativeness and greater NES symptoms. Further research is needed to validate its presence in those with and without comorbid eating disorders and to examine the relative change in NES, eating disorder symptoms and personality scores in treatments focusing on cooperativeness. LEVEL OF EVIDENCE: Level IV (cross-sectional data from a randomised controlled trial, CTB/04/08/139). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40519-021-01221-5.