Fat people are not more jolly, according to a study
that instead found obesity is strongly linked with
depression and other mood disorders.
Whether obesity might cause these problems or is
the result of them is not certain, and the research
does not provide an answer, but there are theories
to support both arguments.
Depression often causes people to abandon activities,
and some medications used to treat mental illness
can cause weight gain. On the other hand, obesity
is often seen as a stigma and overweight people often
are subject to teasing and other hurtful behavior.
The study of more than 9,000 adults found that mood
and anxiety disorders including depression were about
25 percent more common in the obese people studied
than in the non-obese. Substance abuse was an exception
— obese people were about 25 percent less likely
to abuse drugs or alcohol than slimmer participants.
The results appear in the July issue of Archives
of General Psychiatry, being released Monday. The
lead author was Dr. Gregory Simon, a researcher with
Group Health Cooperative in Seattle, a large nonprofit
health plan in the Pacific Northwest.
The results "suggest that the cultural stereotype
of the jolly fat person is more a figment of our imagination
than a reality," said Dr. Wayne Fenton of the National
Institute of Mental Health, which funded the study.
"The take-home message for doctors is to be on the
lookout for depression among their patients who are
overweight," Fenton said.
Both conditions are quite common. About one-third
of U.S. adults are obese, and depression affects about
10 percent of the population, or nearly 21 million
U.S. adults in a given year.
Previous studies produced conflicting results on
whether obesity is linked with mental illness including
depression, although a growing body of research suggests
there is an association.
This latest study helps resolve the question, said
Dr. Susan McElroy, a psychiatry professor at the University
of Cincinnati and editor of a textbook on obesity
and mental disorders.
"This is a state-of-the-art psychiatric epidemiology
study that really confirms that there is, in fact,
a relationship," she said.
The study was based on an analysis of a national
survey of 9,125 adults who were interviewed to assess
mental state. Obesity status was determined using
participants' self-reported weight and height measurements.
About one-fourth of all participants were obese.
Some 22 percent of obese participants had experienced
a mood disorder including depression, compared with
18 percent of the nonobese.
McElroy said the study bolsters previous research
suggesting that drug and alcohol abuse are less common
in the obese. One reason might be that good-tasting
food and substances of abuse both affect the same
reward-seeking areas of the brain, McElroy said. Why
some people choose food as a mood-regulator and others
drugs or alcohol is uncertain, she said.
The study found the relationship between obesity
and mental illness was equally strong in men and women,
contrasting with some previous research that found
a more robust link in women.
