Study finds link between exercise, mental health

A trip to the gym may be able to do more than just improve physical physique — it could potentially improve the mental health of severely depressed individuals.

A Yale study — published yesterday in the biomedical-research publication “Nature Medicine” — indicates that an exercise gene known as VGF works as an effective anti-depressant in the brains of mice. The research, led by psychiatry and pharmacology professor Ronald Duman, found that medicinal doses of VGF could potentially be administered to humans as an alternative to current anti-depression pharmaceuticals, Duman said.

“It is conceivable that VGF could produce a better anti-depressant than what’s available today, or [it could] at least offer an alternative approach,” he said.

For many years, Duman said, scientists were aware of the anti-depressant effects of exercise but were unable to determine its biological cause. Through a process of gene profiling in mice, the Yale research team identified VGF as a possible mechanism for this process, he said.

Duman and Joshua Hunsberger GRD ’03 monitored the brain activity of two groups of mice — one whose members had access to a spinning wheel in their cages and another whose members did not. The mice with spinning wheels presented 33 different exercise genes in brain analysis, of which VGF was the most active.

“We know that exercise has many beneficial effects,” Duman said. “But now we are aware of the specific gene which has anti-depressant effects.”

To test the health benefits of the newly discovered gene, the researchers administered concentrated doses of VGF to one group of mice and blocked the VGF gene in the other group.

The mice who received the VGF doses exhibited the same effects produced by a powerful anti-depressant drug, while blocking the VGF gene caused the mice to experience symptoms of depression.

Psychiatry research scientist Catharine Duman, a secondary author of the study, said exercise is a useful option for patients suffering from depression because there are no chemical-related side-effects.

Unfortunately, she said, severely depressed patients are often unmotivated to participate in physical exercise. Creating a medicinal form of the VGF gene could potentially allow these patients to enjoy the benefits of exercise without the physical work, she said.

“We are looking at pathways and mechanisms which would allow patients to improve without actually having to do the physical activity,” Duman said.

The most promising results of exercise treatment in human tests have been found in aged populations, whose members are already beginning to decline in physical ability, she said.

Damian Hardy, a practicing physical therapist, said while he has no experience with the biological effects of exercise on depression, he sees a significant increase in the mood of his patients after beginning exercise regimes. He said this boost comes as the result of the endorphins released during exercise.

Lead author Duman said it will be some time before actual drug testing can begin.

“We’d have to develop an agent before we can begin actually administering VGF,” he said.

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