If the winter blues have got you down, try hitting a yoga class at the gym. Busting through a strenuous, deep-breathing series of yoga poses could boost your mental health—while toning and stretching your body too.

Yoga has a long history (think: 5,000 years) of claiming topromote both physical and mental health, as well as spiritual growth. But how much of this is due to its recent cultural explosion in the U.S.?

A new review of the best research on the health benefits of yoga, published in Frontiers in Psychiatry, aims to keep the truth about yoga from being stretched too far. Based upon the limited number of studies available, researchers from the Duke University School of Medicine concluded that yoga could be a promising treatment for some mental illnesses:

• Mild depression: In several studies, yoga was effective at relieving the symptoms of mild clinical depression, even when people were not taking antidepressant medications.
• Sleep complaints: Yoga helped people sleep better and longer, which—given the fact that 25 percent of U.S. adults take sleep medications—is nothing to snore at.

These mental health benefits of yoga are not surprising. Other studies have shown that yoga causes chemical changes in the body similar to antidepressants and psychotherapy—such as reduced inflammation and improved neurotransmitters.

More research is needed—most of the studies are small—but it may be time to give it a try. It could keep you smiling and sleeping well all winter long.