The examination of opposite-sex and same-sex dizygotic twins allows
us to explore the sex-specific comorbidity of psychiatric disorders. To date,
this question has not been explored in eating disorders.
To determine whether sex influences shared risk factors between bulimia
nervosa (BN) and other forms of psychopathology.
The study examines associations between BN and other forms of psychopathology
in twin pairs using interview and survey reports.
Twins from the Virginia population-based twin registry.
Male-female dizygotic twins (N = 1192 pairs), mean (SD) age 36.6 (8.9)
years, and female-female dizygotic twins (N = 467 pairs), mean (SD) age 36.0
Main Outcome Measures
Lifetime psychiatric disorders as diagnosed by a structured psychiatric
interview, including major depression, anxiety disorders, and substance abuse
and dependence. Also, continuous measures of body mass index and personality,
including neuroticism and novelty seeking.
Significant within-person associations existed for women between BN
and higher body mass index, neuroticism, novelty seeking, and all lifetime
psychopathology. Results from this study suggest the presence of either familial
or nonfamilial shared risk factors between BN and generalized anxiety disorder,
neuroticism, psychoactive substance use, novelty seeking, major depression,
and panic disorder. The shared risk factors between BN and generalized anxiety
disorder and BN and novelty seeking were only present in men.
Evidence supports the existence of a sex-specific manifestation of familial
liability with respect to BN and generalized anxiety disorder and BN and novelty