Depression increases the levels of stress hormone in adolescents but may cause obesity only in females, a new research has disclosed.

Early cure of depressive disorder could help lessen anxiety and control obesity, which has become a major health problem in today's world.

Elizabeth J. Susman, professor of bio-behavioural health at Penn State University (PSU) said, "This is the first time cortisol reactivity has been identified as a mediator between depressed mood and obesity in girls."

"We really haven't seen this connection in kids before, but it tells us that there are biological risk factors that are similar for obesity and depression," Susman added.

Hormone cortisol controls different metabolic functions and is released as a reaction to nervous tension.

Scientists have long known that depression and cortisol are linked to fatness, but they had not solved the accurate biological method.

Although it is not clear why high cortisol responses turn into fleshiness only for females, researchers thought that it may be owing to physiological as well as behavioural variations -- oestrogen release and stress eating in females in the method the two genders deal with nervousness.

Susman said, "The implications are to start treating depression early because we know that depression, cortisol and obesity are related in adults."

If depression were to be handled in advance, she mentioned, it could help lessen the cortisol level, and thereby help lessen obesity.

"We know stress is a critical factor in many mental and physical health problems," said Susman. "We are putting together the biology of stress, emotions and a clinical disorder to better understand a major public health problem."

Susman and her fello workers Lorah D. Dorn, professor of paediatrics, Cincinnati Children's Hospital Medical Centre and Samantha Dockray, postdoctoral fellow, University College London, utilized a child behaviour checklist to evaluate 111 boys and girls aged bwetween 8 to 13 for depression symptoms.

Next they assessed the kid's obesity and the intensity of cortisol in their saliva before and after different stress examinations.

Statistical studies of the information hinted that depression is connected with spikes in cortisol levels for males and females after the stress experiments, but higher cortisol responses to stress are linked with obesity only in females.

The group reported its discoveries in a recent issue of the Journal of Adolescent Health. (With Input from Agencies)