Am J Psychiatry 164:5, May 2007
As the American Psychiatric Association committees begin formal work on DSM-V, we welcome
brief editorials on issues that should be considered in its formulation.
Issues for DSM-V: Should Obesity Be Included
as a Brain Disorder?
Obesity (body mass index >30), has increased significantly over the past 30 years
(approximately 50% per decade) (1), afflicting 32.2% of adults in the United States (2).
Obesity increases risk for cardiovascular disease, diabetes, cancer, and other diseases,
resulting in annual health care costs conservatively estimated for the United States at
$70 to $100 billion a year (3) as well as reductions in life expectancy by 5 to 20 years (4).
These facts highlight the urgent need to develop strategies to prevent and treat those
Although there have been major scientific advances in the treatment of the medical
complications of obesity (i.e., diabetes, hypertension hypercholesterolemia), the mor-
bidity from this disorder is hampered by the fail-
ure of interventions to sustain weight loss. Stan-
dard interventions based on promoting lifestyle
changes to decrease excessive food consumption
(dieting) and increased physical activity (exer-
cise) are effective and can normalize weight if fol-
lowed rigorously, but unfortunately they are in-
credibly difficult to sustain. The discrepancy
between the successes of the metabolic treat-
ments of consequences of obesity and the fail-
ures of behavioral treatments to prevent or re-
verse obesity highlight the fact that this condition
is not only a metabolic disorder but also a brain
disorder. Consideration of the mental component of obesity should be a key target in the
treatment of obesity to facilitate compliance and minimize relapse. Here, we propose
that some forms of obesity are driven by an excessive motivational drive for food and
should be included as a mental disorder in DSM-V.
DSM-IV recognizes eating disorders such as anorexia and bulimia as mental disorders
with severe impairments and serious adverse outcomes but does not recognize obesity
despite its devastating medical and psychological consequences. Obesity is character-
ized by compulsive consumption of food and the inability to restrain from eating de-
spite the desire to do so. These symptoms are remarkably parallel to those described in
DSM-IV for substance abuse and drug dependence (Table 1), which has led some to
suggest that obesity may be considered a “food addiction” (5).
There are multiple mechanisms contributing to the vulnerability to obesity, including
genetic, developmental, and environmental factors that are likely to interact in diverse
ways among individuals to produce the behavioral phenotype of overeating (6). The
“thrifty genotype” hypothesis suggests that evolution shaped the circuits involved in
how our bodies store food as well as the circuits involved in the procurement of food in
our ancestors when food was scarce. In current environments, where for the most part
food is widely available and diverse, these circuits can lead to food overconsumption.
The “developmental origin hypothesis” suggests that calorie content as well as exposure
to certain nutrients during pregnancy modify how the body and brain develop in anti-
cipation of future environments with similar nutrient characteristics.
What brain circuits are associated with obesity? The hypothalamus is recognized as the
main brain region that controls the regulatory signals for food consumption. The genetic
“Consideration of the
mental component of
obesity should be a key
target in the treatment of
obesity to facilitate