Does Gender Affect Symptoms, Temperament, and Outcome in AN?

The fact that there is a markedly higher prevalence of anorexia nervosa (AN) among females than males has led to speculation about what specific causal factors may differ between men and women. Anecdotal observations have also suggested that men with AN may have more atypical features, such as psychoses, personality disorders and sexual deviance, than females, but less concern with actual weight.

Michael Strober PhD, and colleagues at the David Geffen School of Medicine at UCLA recently found one significant difference between 99 consecutive patients (85 girls and 14 boys) with DSM-IV criteria for AN who were admitted for treatment at the UCLA Neuropsychiatric Hospital, Los Angeles (Int J Eat Disord 2006;39:570). Girls had significantly higher scores on weight concerns on the Eating Disorder Examination.

Both genders had equivalently severe core features of the illness upon admission and comparably high prevalence rates of comorbidity with anxiety disorders. Most were described by their parents as having an “anxious” personality.

Girls had a more prolonged course of illness

After discharge, the girls had a more prolonged course of disease and had more intense weight, shape, and eating concerns when they were reassessed a year after discharge. The authors offer several speculations as to how the females’ greater concerns about weight could help account for these differences, including biological, psychological, and behavioral factors. First, they hypothesized that sexual dimorphisms in brain serotonergic activity (5-hydroxytryptamine [5-HT]) activity and the effects of ovarian steroids on 5-HT pathways may have led to the differences. Other possibilities include changes in brain 5-HT function caused by chronic dieting and social and cultural norms that present a thin weight ideal for girls, which might then lead to fears of weight gain compared with males. Other possibilities include a stronger heritability of anxiety sensitization in females compared with males, and the frequently higher prevalence of behavioral inhibition and neuroticism among females in the general population.

According to the authors, future studies will be needed to determine whether weight concern per se brings heightened risk of a more pernicious long-term illness, or is a risk factor for early relapse only, or is simply a correlate of other later influences that contribute to greater persistence of AN in females than in males.