By Amy Norton
FRIDAY, April 26 (HealthDay News) -- Noninvasive stimulation of an area of the brain linked to addiction seems to temporarily ease smokers' cravings for nicotine, a preliminary study finds.
The technique, called transcranial magnetic stimulation (TMS), is already approved in the United States as a treatment for major depression. In the new study, reported in a recent issue of the journal Biological Psychiatry, researchers tested the effects of the treatment on 16 smokers' craving for nicotine.
They found that in general, the smokers were yearning for nicotine after seeing tempting images -- like a person lighting a cigarette. But after 15 minutes of transcranial magnetic stimulation, that craving dipped by almost 30 percent, on average.
"This is just a pilot study," said lead researcher Dr. Xingbao Li, an assistant professor at the Medical University of South Carolina, in Charleston. "There's still a long way left to go."
During TMS, an electromagnetic coil is placed on the scalp to create electric currents that stimulate cells in a specific area of the brain. The therapy is approved for hard-to-treat cases of depression that do not improve with standard treatments, like antidepressants and talk therapy.
Experts think it works by boosting levels of mood-regulating chemicals like dopamine. That may also be what's happening when it comes to nicotine craving, Li explained, since dopamine levels dip when people are in withdrawal from a drug.
But that's speculation for now, he said.
Another researcher who studies tobacco dependence said the findings, while early, are "quite exciting."
If further research supports it, transcranial magnetic stimulation could be one more tool in the smoking-cessation toolbox, according to Christine Sheffer, an associate medical professor of community health and social medicine at the City College of New York.
Sheffer said she could foresee TMS being an option for smokers, to be used along with behavioral counseling. "I think it is important to stress that it is unlikely that any form of brain stimulation -- or any treatment for that matter -- is going to affect cessation without behavioral treatment," Sheffer said.
The findings are based on 16 smokers who had no designs on quitting, but agreed to undergo transcranial magnetic stimulation. First, they all viewed four collections of images, one of which was aimed at boosting their nicotine craving -- like images of a smoker lighting up. After seeing each collection, the smokers rated their nicotine craving.
Afterward, the smokers sat through 15 minutes of the brain stimulation treatment, then looked at the images again and rated their desire for nicotine.
To help ensure that any effects of the transcranial magnetic stimulation were real, Li's team also had each smoker go through the whole process on a separate day, but with a "sham" version of transcranial magnetic stimulation. The fake device looked and sounded like the real thing, and also gave smokers the same sensation in the scalp. But it didn't deliver the electrical current.
Overall, Li's team found, the real transcranial magnetic stimulation reduced smokers' nicotine craving by close to 30 percent. Their cravings also declined after the phony device, but the decline wasn't statistically significant.
"We don't know how significant this would be in real life," Li said.
The next step, he said, is to see whether a series of brain stimulation treatments over a couple weeks has lasting effects on smokers' cravings. The question of whether the brain stimulation could ultimately affect quit rates will take larger, longer term studies.
Based on what's known from depression treatment, transcranial magnetic stimulation seems safe, Li said. The main side effects are a short-lived headache and scalp discomfort. There also appears to be a small risk of seizure, happening in fewer than one in 1,000 patients.
If transcranial magnetic stimulation were to become an option for smokers, there would also be the issue of cost. When the therapy is used for depression, one session typically costs around $300.
Still, Sheffer said that the more options available to smokers, the better. Right now, the approved treatments include nicotine replacement products, like patches and gums, as well as the prescription drugs varenicline (Chantix) and bupropion (Zyban and generics).
Those options, Sheffer noted, are meant to be used along with behavioral counseling.
According to the American Lung Association, it takes the average smoker five or six "serious attempts" to finally quit. So if one approach fails, the group says, keep trying until you find the combination of therapies that works.