Researchers look into obesity’s links to anxiety and mood disorders

Anxiety and mood disorders are associated with obesity in the US population, according to the results of a survey done on 9,125 people. Unlike previous surveys, this study found no difference between men and women in their association of obesity with psychiatric disorders, according to Gregory Simon, MD, MPH, and colleagues, writing in the July Archives of General Psychiatry.

Social and cultural factors may play a significant role in connecting obesity with depression, Simon said, of Group Health Cooperative in Seattle. “However, we can’t say from the data what the direction of causation is.”

The researchers utilized data from the National Combordity Survey Replication (NCS-R) to examine links between obesity and anxiety, mood, and substance abuse disorders in men and women and whether these were also associated with sociodemographic factors. Interviewers used DSM-IV criteria and assessed study participants using the World Mental Health version of t he World Health Organization (WHO) Composite International Diagnostic Interview. The NCS-R survey was conducted over a one-year period beginning in February 2002 and was the US element of a worldwide study coordinated by the WHO.

The study found that obesity, which is defined as a body mass index (BMI) of 30 or more, was linked to about a 25% increase in the odds of mood and anxiety disorders and a 25% decrease in the odds of substance use disorders. These may sound like modest effects, Simon and colleagues said, but are important for public health concerns because of the already high rates of obesity in America.

The study analyzed only the association between the two conditions and could not determine whether obesity caused mood and anxiety disorders or whether mood and anxiety disorders induced obesity. “Many mechanisms could explain the relationship, and possibly more than one is involved,” Simon noted. “Some people eat more when they’re depressed and some eat less, for example.”

The stigma attached to obesity may also lead to depression, Simon continued. “In social groupings where obesity is more stigmatized, it might be equally true that people who can’t lose weight become depressed, or that depressed people can’t lose weight.”

In analyses of various sociodemographic subgroups, the association of obesity with psychiatric disorders was strongest among respondents who were under 30, had a college education, or were of non-Hispanic white ethnicity. Simon suggested that social and cultural factors may thus be critical in understanding the connection. Similar studies in China and Poland, for example, found that an increase in obesity was linked with less depression.

Simon said he “would imagine – although this study doesn’t provide specific evidence for it – that if obesity and depression vary with educational and cultural settings, then a social environment that stigmatized obesity would produce more depression and anxiety among overweight members of that group.”

Eric Stice, PhD, said, “We’ve seen that behavioral weight-loss interventions reduce weight and also lower depressive symptomatology. But there’s not much evidence that treating psychiatric problems leads to weight loss.” Stice is a senior scientist at the Oregon Research Institute in Eugene.

He went on to say that there is likely a reciprocal relationship. “The stress and rejection caused by obesity lead to mood and anxiety problems, while those problems lead to an increased risk of overeating.”

Stigma is no small concern for the overweight, he said. Stice studies risk factors that predict onset of eating disorders, depression and obesity. “I’m amazed at what coaches, parents, and other children say about overweight kids,” he said.

The NCS-R study results highlight the important links between sociocultural factors associating obesity with psychiatric disorders. To explore this link Simon et al are currently conducting a series of smaller surveys to obtain more information on the interaction of diet, depression, obesity and physical activity.

© Copyright 2007 Insight Journal Online Magazine.

Join the Discussion:

Discuss and ask questions in our community forums

Recommended Links:

Sign up for our FREE Health and Wellness Newsletter
Association Between Obesity and Psychiatric Disorders in the US Adult Population [Archives of  General Psychiatry]
Obesity, Anxiety and Food Consumption [National Institutes of Health]
Insight Journal: Diet and Nutrition
Insight Journal: Anxiety
Insight Journal: Depression


View More Articles In Category: Anxiety News