Posted on July 6, 2009

Studies have already shown that obesity and depression can go hand in hand in adults. Now, new research supports the same theory in children. A new Science Daily piece examines a new study that connects abnormalities of the stress hormone cortisol with symptoms of depression in obese children.

“There is evidence in adults that abnormal regulation of cortisol plays a role in both obesity and depression,” said the study’s lead author, Panagiota Pervanidou, MD, of Athens University Medical School in Athens, Greece, in the Science Daily. “Our study indicates that cortisol abnormalities may underlie obesity and depression starting in childhood.”

A steroid hormone, cortisol helps the body to respond better to stress. It also serves other functions, such as converting fat, protein and carbohydrates into energy. Typically, the levels of this hormone peak early in the morning and start to drop in late morning. By night, this hormone is at its lowest level.

The difference in depressed adults is slightly elevated cortisol levels at night, which contributes to development of the metabolic syndrome. This includes abdominal obesity and other risk factors for diabetes and cardiovascular disease.

Researchers conducting this study found that cortisol levels in the saliva of participants in the afternoon and evening correlated positively with symptoms of depression. It was determined that the more depressive symptoms the subjects reported, the higher the cortisol levels at those times.

According to these findings, obesity and depression may not only be related to behavior, but may also have a hormonal link. As obesity and depression often occur at the same time, prevention and screening should focus on both disorders and should start in childhood to prevent bigger problems and greater obesity later on.

“We recommend that obese children be screened for depression and anxiety, especially female adolescents, who have the highest risk,” Pervanidou added. “In addition, children with a diagnosis of depression should be evaluated for disordered eating, because these patients frequently develop obesity or anorexia.”