Placebos as Good as Drugs For Depression

June 13 -- Antidepressant medications are some of the most widely advertised and widely prescribed drugs in the country. But there's growing evidence that placebos — sugar pills — can often be just as effective at improving mood, and can even improve brain chemistry.

When Americans complain to their doctors about being depressed, the vast majority, 90 percent, are given antidepressants, drugs such as Prozac or Zoloft or Paxil. And while these medications can help relieve depression, clinical trials show that many patients also get better from a simple sugar pill.

"They [patients] don't know whether it's the active medication or the sugar pill but they have a belief that the medication may help and that can contribute to their improvement," Dr. Timothy Walsh, a psychiatrist at Columbia University in New York, told World News Tonight's John McKenzie.

The Placebo Effect

The phenomenon of seeing an improvement while taking a placebo is known as the placebo effect, and is well-known in the field of psychiatry.

For example, a recent study published in the Journal of the American Medical Association designed to test the efficacy of the herbal remedy St. John's Wort compared the herb to a placebo as well as Zoloft.

St. John's Wort didn't perform significantly better than the placebo — but neither did Zoloft. And experts say that this isn't an uncommon occurrence with antidepressant medications.

Dr. Arif Khan, medical director of the Northwest Clinical Research Center in Bellevue, Wash., who does testing for drug companies, analyzed 96 antidepressant trials from a 17-year period. He found that in 52 percent of the trials, there was no significant difference between the placebo and the medication.

"The differences would be like 7 or 8 percent in symptom reduction, which meant the difference was not large enough to be scientifically meaningful," he said.

Khan says most drug companies ran five or more trials to get two showing a significant benefit of a medication over a placebo — the current Food and Drug Administration requirement for approval.