They're called placebos, sugar pills, shams, shots of saline and fake creams. But some argue even though their ingredients may be bogus, the reactions are real. Almost half of all doctors regularly give their patients placebos. Are they con artists or do they know the most effective medicine could be in your head?

It could happen to anyone at any time.

It happened to Jonathan Overman late at night. A car careened into his lane.

"The roof came down over my face and peeled it off," Overman said.

He flat lined six times. After 13 surgeries and hundreds of medications, he was back on his feet, and Overman said placebos helped him get there.

"It's completely all belief. Belief changes and heals," Overman said.

A study out of the National Institutes of Health reports half of doctors prescribe placebos. The most common: Painkillers followed by vitamins, antibiotics and sedatives.

"Somehow, this thought process of anticipation actually does something in the brain that's similar to what happens when you get an active treatment," said Dr. Walter Brown, clinical professor of psychiatry at Brown University and Tufts University School of Medicine.

"There are serious ethical issues of giving someone a treatment that they believe is real when it's not," countered Tor Wager, a psychologist at Columbia University.

The American Medical Association recommends doctors only use placebos if the patient is informed and consents, but can a placebo work if the patient knows it's no more than this? Brown, who teaches at both Brown and Tufts universities, says yes.

"I could prescribe an anti-hypertension medication for you, and we may end up doing that, but a lot of people with your kind of high blood pressure get better by just taking pills like this. These pills don't have any active medicine in them, but they do get certain people better. We don't know how they work," Brown said.

Recent studies show placebos helped reduce tumors in 7 percent of cancer patients. They also helped Crohn's, chronic fatigue syndrome, irritable bowl syndrome and multiple sclerosis, yet not all doctors are believers.

"I don't really think believing can cure. I think that if you have certain beliefs, they might provide comfort. I don't think there's any doubt about that, but I'm not sure that there's really any good evidence that believing can cure disease," said Richard Sloan, professor of behavioral medicine at Columbia University Medical Center.

But for Overman, as his body lay broken, belief kept him going.

"Your belief heals you from within. The human body is something that scientists will never figure out," Overman said.

When it comes to placebos, there is a difference between men and women. The people who are most likely to be placebo responders tend to be those most optimistic, and women tend to respond better. In the future, doctors hope to harness how placebos work and stimulate the brain to enhance treatment, essentially hooking into the body's own natural production of pain relief.

BACKGROUND: According to a new survey, nearly half of American doctors report regularly giving their patients placebo treatments. For the purpose of the survey, the definition of "placebo" went beyond sugar pills. These "treatments" typically included vitamins or harmless drugs such as pain relievers, antibiotics or saline injections, which were disguised as medical therapies. Researchers from the National Institutes of Health sent out surveys to 1,200 internists and rheumatologists. They received 679 responses. Of those who responded, 62 percent found placebo treatments ethically acceptable. About half reported using the placebos several times a month. Of those who used placebos, 70 percent told patients the treatments were "a potentially beneficial medicine not typically used for your condition." Only 5 percent of doctors using placebos directly informed their patients of this fact. The survey found that, in some cases, placebos were given to patients with conditions such as chronic fatigue syndrome. Doctors also gave antibiotics to patients with viral bronchitis even though the virus is unreceptive to these drugs.

DO THEY WORK?: In 1955, in the ground-breaking research paper "The Powerful Placebo," researcher H.K. Beecher concluded that one-third of all patients responded to a placebo. According to the Food and Drug Administration, other studies show up to 75 percent of patients respond to sugar pills. A recent small study published in the Journal of the American Medical Association found antidepressants may be just a little more effective than a sugar pill for most patients. Other research shows placebos can help patients with cancer, irritable bowel syndrome and multiple sclerosis.

IS IT ETHICAL?: Many believe it is unethical for doctors not to disclose the use of placebo treatments to their patients. The American Medical Association's guidelines recommend that doctors only use placebos if the patient is informed and has consented. "In the clinical setting, the use of a placebo without the patient's knowledge may undermine trust, compromise the patient-physician relationship and result in medical harm to the patient," an AMA ethics panel said in 2006. Others argue disclosing this fact would counteract the potential effectiveness of the placebo treatment.