TUESDAY, Jan. 6, 2004 (HealthDayNews) -- In a variation on an age-old question, researchers have long asked themselves which comes first -- obesity or depression?
A new study doesn't resolve the debate, but it does suggest the risk of mental illness is a major problem for the severely obese, and less of a threat for the merely overweight.
Women of average height who weighed more than 240 pounds and men of average height who weighed more than 278 pounds -- defined as morbidly obese -- were five times more likely to be depressed than people of average weight.
However, women who were overweight, but not obese, were also more likely to be depressed.
"It's good news for the general population because it means the depression burden might be lower among the obese than we worry it is," says study co-author Dr. Chiadi U. Onyike, a psychiatric researcher at Johns Hopkins Hospital in Baltimore. "But it's not good news for people who are morbidly obese."
The suspected link between depression and obesity is nothing new. "It seems an obvious connection," Onyike says. But why? Do fat people get depressed because of social stigma, or because of the chemical makeup of their bodies? Or does depression cause a chemical reaction in the body that leads to obesity?
In the new study, the researchers examined statistics from a 1988-94 federal study of the health and nutrition of Americans. They looked at 8,410 people who responded to a psychological questionnaire. The findings appear in a recent issue of the American Journal of Epidemiology.
The people most likely to be depressed -- five times more so than those of normal weight -- were those with a body mass index of more than 40, making them morbidly obese. The index, a ratio of height to weight, is a measurement of obesity.
For people who are 5-foot-4, their BMI will reach 40 when they hit 240 pounds. For those who are 5-foot-10, their BMI will reach that level at 278 pounds.
Among women, simply being obese, a step above being overweight, spelled trouble, but not as much as among the morbidly obese, the study found. The risk of depression doubled among those women who had BMI of 30 or more. That translates to a weight of 180 or more for someone who is 5-foot-5. But the same was not true for men.
The study reveals the importance of screening severely obese patients for signs of depression, says Onyike. "Depression can undermine their compliance with weight-reduction treatments," he says.
But what of the perception that fat people are the life of the party?
Some obese people do indeed seem happy, but that's because they're successfully using food -- a "natural antidepressant" -- to treat their depression, says Dr. Albert Ray, an obesity expert and physician advisor with the Kaiser Permanente Health Plan's Positive Choice Wellness Center in San Diego.
"What a physician normally does is throw a diet at them, [tell them to] go out and exercise and lose weight and come back in a month," Ray says. "It doesn't happen that way. The doctor hasn't gotten to the underlying problem, which is depression or some inner psychological problem."
Once obese people come to terms with their depression, often related to childhood traumas such as abuse, they can begin losing weight, he says. Counseling and medication are often very useful in treating the depression, he adds.
But "there's a lot of denial," Ray says. "These patients don't want to recognize that they're depressed, that they grew up in homes with heavy levels of dysfunction."
More information
To calculate your body mass index, visit this National Institutes of Health site. To learn more about depression, check with the National Institute of Mental Health.
