Researchers have concluded that exercise is being overlooked as a treatment for most mental health disorders, such as anxiety and depression. They base their conclusion on an analysis of dozens of previous mental health studies.

The primary treatments for many mental disorders are cognitive-behavioral therapy, medication or both. What works varies greatly from patient to patient, and sometimes neither type of treatment is effective. Exercise seems to work for nearly everyone.

Just 25 minutes of exercise can improve mood and reduce stress right now. A few exercise sessions will show that a bad mood isn't a barrier to exercising, it's the reason to exercise.

This isn't a particularly new idea, but what is new is the way the researchers suggest that exercise be presented to patients. Patients need to be focused on the immediate benefits exercise brings.

When doctors, psychologists or psychiatrists do prescribe exercise to their patients, they generally focus on the long-term benefits of an exercise program. The researchers think focusing on immediate benefits would work better. Just 25 minutes of exercise can improve mood and reduce stress right now. A few exercise sessions will show that a bad mood isn't a barrier to exercising, it's the reason to exercise. And it doesn't take a great deal of planning or commitment to do so.

People with mental health disorders often have difficulty achieving long-term goals. A depressed person who sets up an exercise program and isn't able to stick to it will just become more depressed. But almost anyone who's physically able can take a spontaneous half-hour walk.

It's been known for years that exercise can act like an antidepressant, changing a person's brain chemistry. This improves the mood of the depressed and helps calm the fears of the anxious. And of course, there are a host of physical benefits to exercise. The problem is getting people to do it. Current recommendations are that people regularly exercise for 30 minutes a day, five times a week Recommendations that focus on a shorter term may be more effective: exercise for 20 or 30 minutes now, feel better today.

Once a patient starts to exercise, it becomes much easier for them to make it a regular part of their life.

This doesn't mean that exercise should be a replacement for behavioral or pharmaceutical treatments. It can supplement them or be used for people who aren't being helped by traditional mental health treatments. All that's needed is for mental health professionals to prescribe it.

The researchers, from Southern Methodist University and Boston University, presented their findings at the 2010 annual conference of the Anxiety Disorder Association of America in Baltimore.