Growing evidence suggests that exercise is as good for your mental health as it is for your physical well-being

Monday mornings, Theo Baars’s exhausting depression often tries to seduce him into just staying in bed. But then, he says, a staffer at Appleton House, a residence for people with psychotic disorders at McLean Hospital, comes into his room and says, insistently, “You want to go work out.”

So Baars, a 22-year-old surfer and musician, drags himself to McLean’s new gym and sweats through a half hour of presses and curls. And then, he finds, he doesn’t want to go back to bed. And more: His confidence is pumped up. His thinking tends to be less delusional, more reality-based.

“Working out helps me get my self back,” he said.

Baars’s personal experience reflects longstanding wisdom that is now gaining the added heft that comes from carefully conducted research. Exercise, the studies increasingly suggest, may be as good for your brain as it is for your body, whether you are mentally ill or not.

As Cambridge psychiatrist and author Dr. John Ratey puts it, if exercise could be bottled, it would be the greatest blockbuster drug ever. “Exercise is medicine for the brain,” he said.

Initial studies show that schoolchildren on a vigorous exercise program score better on standardized tests and are less prone to violence, Ratey writes in “Spark,” a new book on exercise and the brain. He tells people that going for a run is like taking a bit of Prozac - to lighten mood - and a bit of Ritalin - to heighten attention.

Much of the recent research has focused on experimental exercise programs for people with psychiatric disorders, mainly depression, and the carefully controlled clinical trials have turned up dramatic findings.

“There is growing evidence that exercise may be an effective treatment for patients with clinical depression, and that its effectiveness may be comparable to other established treatments such as antidepressant medications,” said Dr. James A. Blumenthal, a professor of medical psychology at Duke University who has led some of the seminal studies.

Last year, his team reported that among 202 depressed people randomly assigned to various treatments, three sessions of vigorous aerobic exercise a week proved about as effective at beating back depression as daily doses of Zoloft, when the effects were measured after four months.

In another study, he found that depressed patients who got better with exercise were less likely to relapse after 10 months than those helped by antidepressants. And patients who continued to exercise after the four-month mark were 50 percent less likely to be depressed months later than those who were sedentary, Blumenthal said.

Other studies suggest that exercise may be about as effective as psychotherapy, the other main tool for alleviating depression, said Michael Otto, a Boston University professor of psychology. He led a 2006 review of research on exercise and mental health, published in Clinical Psychology.

Although there is less hard data on mental disorders other than depression, he said, early studies suggest that exercise may help with many of them, particularly anxiety and possibly addiction. Among ongoing work: Boston University’s Center on Anxiety and Related Disorders is starting a study to see whether running helps smokers quit (bu.edu/anxiety).

Otto calls the documented effects of exercise on mental health “huge” and “surprising.” Still, he says, many clinicians are slow to adopt exercise as part of their treatment arsenal, or to give it the emphasis that the data suggest it may deserve.

Among psychiatric hospitals, many allow walks and offer some exercise equipment, but it is often minimal.

McLean’s two-year-old gym came about in large part thanks to Kay Kimpton Walker, a San Francisco-based member of the hospital’s national council. While a relative of hers was living at Appleton House, she said, he found that daily runs helped him greatly, and some of his housemates often straggled after him. She spearheaded the effort to raise $400,000 to rehab a room into a gym and adjacent hang-out area.

More hospitals would surely create better gyms if they had the money, she said, “but equally important is that somebody needs to say, ‘Why don’t we have this? We need to have it.’ “

Staffing can also be a problem, said Carrie Brown, the fitness coordinator at McLean, who is always present during patient hours. The gym logs about 600 visits per month from among about 375 patients who are eligible. The two groups that use the gym most - short-timers and longer-term residents - are clearly using it heavily, and would work out more if they had more time in their busy therapeutic schedules, she said.

Some people in the throes of a mental health crisis may simply feel unable to exercise. And yet another problem, said Ratey, who was once the director of Medfield State Hospital: “It really comes back to the lawyers,” who worry about liability in case of a mishap. (The McLean gym has seen nothing worse than a patient who tripped on the treadmill.)

Researchers at McLean are gathering data to show the gym’s effects on patients, but Brown can already attest anecdotally to the benefits. She constantly sees patients who come in downcast and worn out, and in the course of a work-out, become more alert, more talkative, even uplifted.

Why should moving the body so affect the brain? Ratey points to several apparent mechanisms. They include:

Exercise tends to foster brain chemicals that act like “Miracle-Gro” for nerve cells, he says.

It also affects neurotransmitters such as serotonin, which are known to influence mood.

And recent studies also suggest a role for a stress-reducing hormone produced in heart muscle called ANP; as the heart works harder, the body produces more ANP, which helps control the brain’s response to stress and anxiety.

It always takes time for research findings to work their way into the daily practice of community doctors, Otto said. He and a colleague have just begun working on a manual for clinicians to help them prescribe exercise. But in the meanwhile, he said, patients can ask their physicians, “Can you do this with me?’ “

By Carey Goldberg
Globe Staff

Carey Goldberg can be reached at .(JavaScript must be enabled to view this email address).