Zoloft is one of the many drugs to battle depression. As it does, it can also create, according to the Nurses Drug Guide, 55 adverse side effects, including chest pain, blurred vision, loss of hair, nausea, vomiting, diarrhea, paranoia, and suicidal thoughts.

Oh, and males can develop breasts and lose sexual function.

Running is one of the many exercises used to battle depression. As it does, it can also create, according to any runner's guide, a few adverse side effects, including blisters, shin splints, runner's knee, and plantar fascia.

Oh, and males and females can develop sore quadriceps and hamstrings.

Which set of side effects would you prefer to risk?

In 1998, a meta-analysis of 80 studies in 1998 found that regular exercise effectively reduced clinical depression. In 1999, a single study published in the Archives of Internal Medicine found that 16 weeks of exercise had virtually the same success rate as 16 weeks of Zoloft.

Subsequent studies have consistently found working out to work just as well as drugs used to lessen depression, so don't be swayed by the way the media reported the results of research published in the June issue of the British Medical Journal.

Headline after headline led you to believe that exercise does not help battle depression, but if you read the ends of articles or did a bit of additional research, you discovered that the original goal of researchers was not I repeat, not to draw a conclusion about exercise's effectiveness

What the Brits needed to know was whether or not a program called TREAD (TREAtment of Depression with physical activity) was worth the money that would be required to add it to their healthcare plan. TREAD allows patients to receive as many as three face-to-face meetings and 10 phone conversations with a motivational coach whose goal is to get the patient to exercise.

To determine TREAD's effectiveness, researchers from the Universities of Bristol, Exeter and the Peninsula College of Medicine and Dentistry, recruited 361 adults who had been previously diagnosed with depression. Some continued to receive what is considered customary care, whatever options their personal doctor prescribed. Others received customary care plus the TREAD treatment.

When the two groups were compared one year later, TREAD treatment subjects were not less depressed than those who only worked with their doctors. That finding is what precipitated the headlines that insinuated exercise doesn't battle depression.

But the efficacy of exercise in the battle against depression really couldn't be determined from the results of the study for a number of reasons.

First and foremost, it's probable that many of the subjects under only their doctor's care were not only exercising, but also exercising more than some in the TREAD group. After all, since the British government suggests that adults do 150 minutes of vigorous exercise a week, it's assumed that most British doctors suggest the same, yet the motivational counselors working with the TREAD treatment subjects were asking for no more and possibly less that.

TREAD counselors advised moderate-to-vigorous activity in at least 10-minute increments to reach the 150-minute mark, but would accept lesser time or intensity if the subjects found that goal unrealistic.

In essence, the only certain difference between the groups in the study was the coaching.

Another element to the study that could potentially skew results is that the exercise reporting came primarily through dairies, a process known to lead to inaccuracies, though accelerometers were used as a way to double check.

Even the remarks of lead author, Melanie Chalder, from University of Bristol's School of Social and Community Medicine, made it clear that this study was not an indictment upon exercise's ineffectiveness in battling depression, just the TREAD program. To the press, she said: "This study does not tell us whether other types of support or exercise programs may have a positive effect on depression."

Other studies, however, certainly have.

One, led by Dr. Madhukar H. Trivedi, a professor of psychiatry at the University of Texas Southwestern Medical Center, took 126 sedentary people who had been on antidepressants without success for at least two months and had them exercise in one of two ways.

In one group, exercise was judged by caloric expenditure rather than intensity. The other group did 30 minutes of brisk walking or cycling each day. In four months, 29.5 percent of all in the study were in remission.

That percentage may not sound impressive until you realize it's a bit better than the 20-to-30-percent remission rate achieved when when patients who have not improved with one drug are given a second one. It's also far cheaper and safer.

Another interesting element to the study is that the group engaged in the more vigorous exercise had a higher success rate, even though females following the lighter exercise program fared better than females exercising briskly 30 minutes a day.