A new study shows that kids who are substantially overweight throughout much of their childhood and adolescence have a higher incidence of depression than those who aren't.
The research, published in the April issue of Pediatrics, studied nearly 1,000 children for a period of eight years to learn whether being obese had any links to psychological problems.
"The most significant finding was that chronic obesity is linked to psychiatric disorders in children and adolescents," says Sarah Mustillo, study author and a researcher in the Department of Psychiatry and Behavioral Sciences at Duke University School of Medicine.
Although media attention is often focused on the weight of young girls, surprisingly it was young boys who were at greatest risk for weight-related depression. However, the study also found that chronically obese boys and girls were at risk for "oppositional defiant disorder" -- a behavior problem typified by combative, hostile or uncooperative behavior toward authority figures.
While the study makes a clear association between chronic obesity and psychological problems, what it doesn't do is draw a line of blame from one to the other. According to Mustillo, researchers don't know for sure what comes first -- the depression or the obesity.
"If I had to speculate about the connection, I would propose two possible avenues -- social and neuroendocrine," Mustillo says.
First, she says, obesity could influence treatment -- such as teasing -- from peers that, in turn, courts depression. Perhaps more important, Mustillo points out that both obesity and psychological disorders may share a brain chemistry that is ultimately responsible for both problems.
For childhood obesity expert Dr. Henry Anhalt, the real value of this study is not just the links to psychological problems, but the recognition that the cause of obesity is not the same for all affected.
"What is of enormous importance in this study is the recognition that obesity is not a clear-cut and simple problem, that it is not the same for every person," says Anhalt, director of pediatric endocrinology at Infants and Children's Hospital of Brooklyn at Maimonides Medical Center in New York City.
What the study really shows, he says, is how complex a problem obesity is -- particularly in children -- and the need for a wide variety of treatment options.
"I think the real breakthroughs in treatment will come when we fully recognize all the ways in which obesity can affect an individual patient," Anhalt says.
The new study involved 991 white children from the Great Smokey Mountains in North Carolina, aged 9 to 16. Each child was evaluated yearly for eight years for changes in height, weight, psychiatric status and a condition Mustillo called "vulnerability towards psychiatric disorder."
The researchers also divided the children into four groups according to weight specifics: Non-obese (73 percent); chronically obese -- lasting through childhood and adolescence (15 percent); obese only as young children (5 percent); and obese only as adolescents (7 percent).
Since there is no accepted standard of obesity in children, those classified as such were significantly overweight.
After analyzing all the data, two distinct factors defined the research, Mustillo says. First was the realization that childhood obesity in the United States is a greater problem than anyone thought -- some three to four times more common than what had been projected nationally by the U.S. Centers for Disease Control and Prevention in 2000.
Second, the researchers learned that children who were chronically obese had an increased risk for psychiatric disorders -- specifically, depression, which was greater for boys than girls, and oppositional defiant disorder, the same for both boys and girls. Children in the other weight categories did not share the same risks.
Based on her findings, Mustillo offers this advice: "In dealing with children who are already obese, parents may do well to emphasize the health aspects as opposed to the appearance aspects of losing weight ... and both doctors and parents should encourage, model and support nutritious eating and higher levels of physical activity."
To learn more about how to help your child overcome obesity, check out the free booklet What's A Parent To Do, from the U.S. Department of Agriculture. For more information on depression in children, visit The National Alliance for the Mentally Ill.