"Ask your doctor," drug ads urge. If you do, you're much more likely to get a prescription — whether you need it or not.

That's the finding from a study in which trained actors went to 152 doctors in three cities. The actors played patients with clinical depression (for whom antidepressant drugs are appropriate) or patients with job loss and depressed mood (whom antidepressant drugs are unlikely to help).

Some of the mock patients asked the real primary care doctors for Paxil, an advertised, brand-name antidepressant drug. Others either asked in general terms whether antidepressant-type drugs might help them or made no request.

The idea was to look at how drug ads aimed at patients affect the way doctors practice medicine, says researcher Richard L. Kravitz, MD, MSPH, director of the Center for Health Services Research in Primary Care at the University of California, Davis. The study appears in the April 27 issue of The Journal of the American Medical Association.

Ask and You Shall Probably Receive

The study results:

—People who ask doctors for antidepressant drugs are much more likely to get them — no matter how severe their condition.

—Patients with major depression are more likely to get proper treatment if they ask about antidepressant drugs.

—Patients with major depression were just as likely to get a prescription for antidepressants when they requested a specific drug as when they made a general request.

—Patients asking for a specific brand-name drug — in this case, Paxil — were far more likely to get that drug than another antidepressant.

—Patients with minor depression were more likely to get a questionable prescription if they asked for a brand-name drug.

"The short message here is to be careful what you ask for, because you will probably get it," Kravitz tells WebMD. "That can be a good thing in the case of patients who really warrant aggressive treatment. But it can be a bad thing for patients on the clinical margin."

The study took place in San Francisco and Sacramento, Calif., and in Rochester, N.Y. Leading the Rochester part of the study was Ronald M. Epstein, MD, director of the Center to Improve Communication in Health Care and associate dean for educational evaluation and research at the University of Rochester.

"The first thing we found was that advertising works: It sells drugs," Epstein tells WebMD. "And second, we found that doctors are human. They want to satisfy patients while trying to do the right thing. Third, patients have a very powerful influence on what doctors do. This is for better and for worse."

Manufacturer Responds

Nancy Leone, spokeswoman for Paxil maker GlaxoSmithKline, says the study has a flaw. During the study period, she says, GlaxoSmithKline ran ads only for an extended-release version of Paxil, Paxil CR.

"There were two Paxil CR, not Paxil, ads on air," Leone says. "One educated patients about the symptoms of depression and was on the air for one month. The other was to help people with seasonal affective disorder identify their problem, and that was on for three months. So if the study was designed to see if patients get the product advertised, there is a bit of a disconnect in the way the study was conducted."

Direct-to-Consumer Drug Ads Affect Health Care

In an earlier study, Kravitz and colleagues found that in 7 percent of office visits, U.S. patients ask for advertised drugs. Up to 15 percent of these patients say they would look for another doctor if they didn't get the drugs they asked for.

Is this improving the care doctors give to their patients?

Drug companies say it is. Pharmaceutical Research and Manufacturers of America — PhRMA — represents the pharmaceutical and biotechnology industry. PhRMA did not respond to WebMD's invitation to discuss the Kravitz study. But PhRMA's web site carries a 17-page document arguing that drug ads aimed at patients are good for the nation's health.

PhRMA's main points:

—Drug ads make people aware of the risks and benefits of new drugs.

—Drug ads prompt the diagnosis and treatment of undertreated diseases.

—Drug ads give patients vital information.

—Drug ads encourage patients to take the medicines their doctors prescribe.

—By getting patients to talk with their doctors, drug ads strengthen the doctor-patient relationship.

Isn't an Informed Patient Better?

The Kravitz study offers support for some of these claims. When patients who need treatment ask for brand-name drugs — or when they ask in a general way whether drug treatment might help them — the study shows they are more likely to get proper treatment. In this way, the study shows a benefit for drug ads.

On the other hand, when patients don't need treatment, the study shows that asking for a brand-name drug increases the chance that they will get a prescription. Since even the safest drugs carry some risk of side effects, such patients take these risks but are likely to get very little benefit in return.

"If patients make a request for medication, it is not only likely to change what the doctor does but also likely to change what the doctor thinks is right for that patient," Epstein says. "It may make the doctor think an illness is more severe, or that a patient is more in need of a prescription, than the doctor otherwise would have thought."

But isn't a more informed patient a better patient?

GlaxoSmithKline's Leone says that's the point of direct-to-consumer ads.

"By increasing awareness about depression, we hope to enhance the doctor-patient relationship," she says. "And direct-to-consumer ads can encourage patients to visit a doctor about symptoms, especially patients who might not visit doctors otherwise. But ultimately, we feel it is the role of doctors to determine the proper treatments for their patients."

"There is a difference between information and promotion," Epstein says. "When doctors are presented with informative media — if the patient says, 'I saw this TV special on depression' — they are more likely to do the right thing than when a patient comes in with promotional material — 'Here is this ad for Paxil.' And in our study, doctors more often prescribed the drug correctly when the patient made a general request, and more often prescribed the drug incorrectly when they asked for Paxil by name."

GlaxoSmithKline is a WebMD sponsor.

Drug Information and Drug Promotion

In an editorial accompanying the Kravitz study, University of Washington internal medicine specialist Matthew F. Hollon, MD, MPH, says direct-to-consumer drug ads encourage patients to seek treatments they don't need.

The $3.2 billion drug companies spend each year on drug ads are a "haphazard approach to health promotion driven by an industry trying to make a profit," Hollon tells WebMD. "Every time researchers sit down and look at the content of these ads, they find them persuasive and not informative."

Hollon's argument is that drug ads use sophisticated marketing techniques to give their products an emotional appeal.

"Rather than relying on an emotional appeal, ads that actually present data about the magnitude of treatment effects would probably go a long way toward letting patients judge the value of a specific medicine to their health and well-being," he says.

Kravitz says it's not the pharmaceutical industry's job to do this.

"One alternative suggested by our group is that there could be a surtax or charge at the federal or state level, so a portion of the dollars put into consumer ads could support public service announcements that alert the public to the signs and symptoms of important conditions," he says. "So I would like to restore balance in drug advertising by partially funding such announcements through drug industry."

Hollon and Epstein think this is a great idea. But Hollon is skeptical that such public service ads — even if they become a reality — can counter the influence drug ads have on patients and their all-too-human doctors.

"If New Zealand passes a ban on direct-to-consumer drug ads, the U.S. will be the only industrialized country not to limit them," he says. "When I think of the additional cost this kind of advertising adds to health care — and the lack of a compelling public health benefit — I wonder if it should be in existence at all."

GlaxoSmithKline's Leone says drug ads already have sufficient regulation.

'It is important to point out that direct-to-consumer advertising is regulated by the FDA to ensure balance," she says. "All direct-to-consumer advertising campaigns are cleared and reviewed by the FDA, and we follow FDA guidelines."

By Daniel J. DeNoon, reviewed by Michael W. Smith, MD

SOURCES: Kravitz, R. The Journal of the American Medical Association, April 27, 2005; vol 293: pp 1995-2002. Hollon, M. The Journal of the American Medical Association,April 27, 2005; vol 293: pp 2030-2033. Mintzes, B. Journal of the Canadian Medical Association, Sept. 2, 2003; vol 169: pp 405-412.Holmer, A. The Journal of the American Medical Association, Jan. 27, 1999; vol 281: pp 380-384. Hollon, M. The Journal of the American Medical Association, Jan. 27, 1999; vol 281: pp 382-384. PhRMA. Richard L. Kravitz, MD, MSPH, director, Center for Health Services Research in Primary Care, University of California, Davis. Ronald M. Epstein, MD, director, Center To Improve Communication in Health Care, and associate dean for educational evaluation and research, University of Rochester, N.Y. Matthew F. Hollon, MD, MPH, assistant professor, University of Washington, Seattle.Nancy Leone, product communications manager, GlaxoSmithKline.