Associations Between Body Weight and Personality Disorders in a Nationally Representative Sample

OBJECTIVE: To determine whether, in the general population, individuals in numerous abnormal body weight categories had higher odds of having personality disorders (PDs) than normal-weight individuals. Although personality functioning is hypothesized to be associated with body weight, there is a dearth of empirical evaluation of this topic. METHODS: The association of body weight (five categories: underweight [body mass index [BMI] <18.5]; normal [18.5 <or= BMI <25]; overweight [25 <or= BMI <30]; obese [30 <or= BMI <40]; and extremely obese [BMI >or=40]) with personality disorders was investigated using data from the nationally representative National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) (n = 43,093). Lifetime paranoid, schizoid, antisocial, histrionic, avoidant, dependent, and obsessive-compulsive PDs were examined, as assessed by the Alcohol Use Disorders and Associated Disabilities Interview Schedule-DSM-IV version (AUDADIS-IV). RESULTS: After adjusting for sociodemographics, Axis I disorders, schizophrenia, physical health conditions, and comorbid PDs, extreme obesity was associated with antisocial or avoidant PDs (adjusted odds ratio (AOR) range = 1.66-1.73), whereas underweight was associated with increased odds of schizoid PD (AOR = 1.89). The pattern of associations differed when stratified by gender. Overweight men had lower odds of paranoid PD (AOR = 0.73). Women with higher-than-normal body weights had higher odds of paranoid, antisocial, and avoidant PDs (AOR range = 1.33-2.50), whereas underweight women more often met the criteria for schizoid PD (AOR = 1.95). CONCLUSIONS: Higher-than-normal body weight is associated with paranoid, antisocial, and avoidant PDs for women, whereas overweight men have lower rates of paranoid PD and underweight women have higher odds of schizoid PD. Possible clinical implications of this research are discussed.