329Feeding and
Eating Disorders
Feeding and eating  disorders are characterized by a persistent disturbance of eat-
ing or eating-related behavior that results in the altered consumption or absorption of
food and that significantly impairs physical he alth or psychosocial functioning. Diagnos-
tic criteria are provid ed for pica, rumination disorder, avoidant/restrictive food intake
disorder, anorexia nervosa, bulimia nervosa, and binge-eating disorder. 
The diagnostic criteria for rumination diso rder, avoidant/restrictive food intake dis-
order, anorexia nervosa,  bulimia nervosa, and binge-eating  disorder result in a classifica-
tion scheme that is mutually ex clusive, so that during a sing le episode, only one of these
diagnoses can be assigned. The rationale for this approach is that, despite a number of
common psychological and behavioral features , the disorders differ substantially in clin-
ical course, outcome, and treatment needs. A diagnosis of pica, however, may be assigned
in the presence of any other feeding and eating disorder.
Some individuals with disorders described in  this chapter report eating-related symp-
toms resembling those typically endorsed by individuals with substance use disorders,
such as craving and patterns of compulsive use. This resemblance may reflect the involve-
ment of the same neural systems, including th ose implicated in regulatory self-control and
reward, in both groups of disorders. Howeve r, the relative contributions of shared and
distinct factors in the development and perp etuation of eating an d substance use disor-
ders remain insuffic iently understood.
Finally, obesity is not included in DSM-5 as  a mental disorder. Obesity (excess body fat)
results from the long-term excess of energy in take relative to energy expenditure. A range