Relationships between obesity, bipolar spectrum features, and personality traits: a case-control study.

Recently there has been widening stream of research on the relationships between obesity and mental disorders. Patients with obesity seem to be prone to developing bipolar spectrum disorders and they present with specific personality traits. The aim of this study was to analyze the associations between obesity, bipolarity features, and personality traits.A nested case-control study was performed. Patients with obesity constituted the sample of cases (N = 90), and healthy individuals were ascribed to the control group (N = 70). The lifetime presence of bipolarity features was analyzed with the Mood Disorder Questionnaire (MDQ), while personality traits were assessed with the NEO-Five Factor Inventory (NEO-FFI).Bipolarity features were more prevalent in the patients with obesity, as compared to healthy individuals. Patients with obesity had both higher mean value of MDQ score (p = 0.01) and a higher proportion of subjects with MDQ score ≥ 7 points (p = 0.012) as well as lower score on the NEO-FFI openness to experience (p > 0.001), compared to control subjects. Using multivariate model, in patients with obesity, a significant positive correlation between bipolarity and neuroticism, and negative with agreeableness and conscientiousness was established. Such relationship was not observed in control subjects.In the population of patients with obesity, there is a specific combination between bipolarity and personality traits (high-trait neuroticism, low-trait conscientiousness, and low-trait agreeableness). This may have some consequences for both pharmacological and psychological management of such patients.