There are a growing number of available methods that can be
tried in the effort to reduce smoking, including medications, behavioural
therapies, hypnosis, and even acupuncture. All attempt to alter brain function
or behaviour in some way.
How the research was
A new study published in Biological
Psychiatry now reports that a single 15-minute session of high frequency
transcranial magnetic stimulation (TMS) over the prefrontal cortex temporarily
reduced cue-induced smoking craving in nicotine-dependent individuals.
Nicotine activates the dopamine system and reward-related regions
in the brain. Nicotine withdrawal naturally results in decreased activity of
these regions, which has been closely associated with craving, relapse, and
continued nicotine consumption.
One of the critical reward-related regions is the
dorsolateral prefrontal cortex, which can be targeted using a brain stimulation
technology called transcranial magnetic stimulation. Transcranial magnetic
stimulation is a non-invasive procedure that uses magnetic fields to stimulate
nerve cells. It does not require sedation or anesthesia and so patients remain
awake, reclined in a chair, while treatment is administered through coils
placed near the forehead.
Dr. Xingbao Li and colleagues at Medical University of South
Carolina examined cravings triggered by smoking cues in 16 nicotine-dependent
volunteers who received one session each of high frequency or sham repetitive
transcranial magnetic stimulation applied over the dorsolateral prefrontal
cortex. This design allowed the researchers to ferret out the effects of the real
versus the sham stimulation, similar to how placebo pills are used in
evaluating the effectiveness and safety of new medications.
They found that craving induced by smoking cues was reduced
after participants received real stimulation. They also report that the
reduction in cue-induced craving was positively correlated with level of
nicotine dependence; in other words, the TMS-induced craving reductions were
greater in those with higher levels of nicotine use.
Help for smokers
Dr. John Krystal, Editor of Biological Psychiatry,
commented, "One of the elegant aspects of this study is that it suggests
that specific manipulations of particular brain circuits may help to protect
smokers and possibly people with other addictions from relapsing."
"While this was only a temporary effect, it raises the
possibility that repeated TMS sessions might ultimately be used to help smokers
quit smoking. TMS as used in this study is safe and is already FDA approved for
“This finding opens the way for further exploration of the
use of brain stimulation techniques in smoking cessation treatment," said