vation suggest that obsessions and compulsi ons related to food may be exacerbated by
undernutrition. When individuals with anorexia nervosa exhibit obsessions and compul-
sions that are not related to food, body shape, or weight, an additional diagnosis of obses-
sive-compulsive disorder (OCD) may be warranted.
Other features sometimes associated with anorexia nervosa incl ude concerns about
eating in public, feelings of ineffectiveness, a strong desire  to control one’s environment,
inflexible thinking, limited social spontaneity, and overly restrained emotional ex-
pression. Compared with indivi duals with anorexia nervosa, restricting type, those with
binge-eating/purging type have higher rates of impulsivity and are more likely to abuse
alcohol and other drugs. 
A subgroup of individuals with anorexia ne rvosa show excessive levels of physical ac-
tivity. Increases in physical activity often precede onset of the disorder, and over the
course of the disorder increased activity ac celerates weight loss. During treatment, exces-
sive activity may be difficult to control,  thereby jeopardizing weight recovery.
Individuals with anorexia nervosa may misu se medications, such as by manipulating
dosage, in order to achieve we ight loss or avoid weight ga in. Individuals with diabetes
mellitus may omit or reduce insulin doses in order to minimi ze carbohydrate  metabolism. 
Prevalence
The 12-month prevalence of anorexia nervosa among youn g females is approximately
0.4%. Less is known about prevalence among ma les, but anorexia nerv osa is far less com-
mon in males than in females, with clinical populations generally reflecting approximately
a 10:1 female-to-male ratio. 
Development and Course