Most people to whom antidepressants are prescribed do not benefit from them, according to an article recently published in the Journal of the American Medical Association. This is crucial news for psychiatrists and their patients, but it is also, as Congress makes its final push towards health care reform, important news for anyone interested in the high costs of medical care. With sales totaling almost $10 billion a year, antidepressants account for almost 15% of the total cost of medication in the US. It seems that most of that money is simply going down the drain.

The findings in last week’s paper shouldn’t have been a total surprise. The new study comes on the heels of previous research showing that antidepressant drugs are not much better than placebos — sugar pills with no active ingredient at all — for most depressed patients. People who are given antidepressants in clinical trials do improve, but so do people who are given placebos. The drugs have beneficial effects, but they are not drug effects; they are placebo effects. It is only at very extreme levels of depression that the drugs seem to have a clinical effect.

The causes of depression are complex. It has been linked to poverty, unemployment, discrimination, the loss of a loved one and faulty ways of thinking that have been learned in childhood. Depression is not just the result of a chemical imbalance in the brain. But most importantly, it is characterized by a sense of hopelessness — a feeling that one will never get better. Placebos are effective because they instill a sense of hope.

So what should we do? Depression can be a severely disabling condition, causing immense suffering to patients and their families and costing billions of dollars each year in the form of lost work productivity. Clearly, it cannot be left untreated. But it is equally clear that spending billions on ineffective pills is not the answer.

Fortunately, there is a treatment that has been shown to produce more lasting improvement than either drugs or placebos. It’s a form of psychotherapy called cognitive behavior therapy, or CBT. In one study, 60% of patients successfully treated by CBT remained free of depression six years later. In contrast, most patients treated with antidepressants relapse within a year or two.

The biggest surprise — and the one most germane to the argument over health-care reform — is that treatment with psychotherapy may be less expensive than treatment with medication. The reason is that depressed people may have to be kept on antidepressants for years to keep them from getting worse again. CBT treatments last only 10-20 weeks, and the effects seem to last even without further counseling.

Frustratingly, however, insurance companies are more likely to cover the cost of drugs than CBT.

Psychotherapy may not be the only treatment that is effective in combating depression. Studies on physical exercise have also shown promising results. Twenty minutes of exercise three days a week seems to be enough to produce an antidepressant effect, and the type of exercise does not seem to matter much. Walking and running are equally effective as aerobics or weight lifting, and the costs are minimal.

The benefits of physical exercise in the treatment of depression might also be a placebo effect. But consider the differences between exercise and antidepressants. Side effects of antidepressants include sexual dysfunction, nausea, vomiting, insomnia, drowsiness, seizures, diarrhea and headaches. Side effects of physical exercise include enhanced libido, better sleep, decreased body fat, improved muscle tone, greater life expectancy, increased strength and endurance and improved cholesterol levels.

Which placebo would you prefer?

There are also self-help books, such as David Burns’s “Feeling Good” and Peter Lewinsohn’s “Control Your Depression,” that have been found effective in treating mild depression in clinical trials. These books and programs are based on CBT.

The British government has started a program aimed at training 10,000 new therapists, so that CBT can be made available to patients for free by the National Health Service. How can they afford to do this, even in the current economic crisis? Because they figure the cost of short-term psychotherapy to be about $1,200 per patient, but the government would save more that $1,400 per patient per year in reduced incapacity benefits and higher taxes alone, not to mention the costs that would be saved by fewer medication prescriptions and hospitalizations for depression.

So the real question is not how can they afford to make psychotherapy available to depressed patients, but how can they afford not to?

Perhaps we can learn from the Brits, as we consider the treatment of depression in the context of health reform in the US. Depression costs the US economy an estimated $44 billion per year. Providing effective treatment is not only a moral imperative. It makes economic sense as well.

Irving Kirsch is a professor of psychology at the University of Hull in the UK and a professor emeritus at the University of Connecticut. His book, “The Emperor’s New Drugs: Exploding the Antidepressant Myth” (Basic Books), is out this month.