Stimulating brain activity may provoke relapse when smokers are attempting to quit, scientists have revealed.
These astonishing new findings could pave the way for more targeted treatments for everything from drug and alcohol abuse to obsessive-compulsive disorders.
There are many methods that smokers use in an attempt to reduce their craving for cigarettes, including efficacious pharmacologic treatments such as nicotine patches, and alternative approaches such as hypnosis and acupuncture.
Scientists have long suspected that these diverse approaches might work through a common mechanism - the reduction of activity in a brain circuit that is responsible for cigarette craving.
This hypothesis is supported by human functional brain imaging studies, which consistently report the activation of several brain regions during craving that involve regions in the cerebral cortex as well as the limbic system, a brain circuit involved in emotion.
Building on these brain imaging studies, scientists at the Centre for Nicotine and Smoking Cessation Research at Duke University Medical Centre manipulated this 'craving circuit' activity using transcranial magnetic stimulation (TMS), a non-invasive technique that uses electromagnetic currents to target specific or general areas of the brain.
Depending upon the frequency used, it can either stimulate or depress brain activity.
The researchers found that the delivery of repeated TMS to the superior frontal gyrus at high frequency (10 Hz) increased craving for cigarettes.
"We directly stimulated a frontal brain region using magnetic fields and showed that it exaggerated smokers' craving for cigarettes when they viewed smoking related cues," explained Dr. Jed Rose, one of the study authors.
"By gaining a better understanding of how the brain influences craving responses, strategies for blocking these responses can be devised and ultimately more effective smoking cessation treatments may be developed," he added.
The study appeared in Biological Psychiatry.