Stimulating specific regions of the brain with weak electrical currents may help smokers give up tobacco, according to new research. After pooling data from all available research on the subject, the authors found that the technique enhances quitters’ chances of remaining abstinent for up to six months.
Referred to as non-invasive brain stimulation (NIBS), the treatment can be performed using electrodes that deliver a low-intensity current through the scalp or a metallic coil that sends magnetic pulses through the brain. Known as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) respectively, these two methods are currently being explored as potential treatments for substance use disorders, depression, and other mental health issues.
In 2020, the FDA approved the use of a particular TMS system for short-term smoking cessation, after a study involving 262 smokers revealed that the treatment helps people quit for up to four weeks at a time. To determine if NIBS can facilitate longer-term abstinence, the authors of the new paper published in Addiction conducted a systematic review of all randomized controlled trials using the technique.
A total of seven trials were identified, involving 699 participants. In each study, smokers were treated with either NIBS or a sham form of the treatment, which acted as a placebo. Changes in smoking behavior were then recorded for a period of between three and six months after treatment.
Overall, smokers who received NIBS were 2.39 times more likely to remain abstinent long-term than those who underwent the sham therapy. This success rate is superior to other smoking cessation aids, such as varenicline, which is associated with a 224 percent increase in the likelihood of abstinence after six months, as well as e-cigarettes, which enhance the chances of quitting by 194 percent.
In a statement, lead author Dr Benjamin Petit said that “while our review appears modest, with only seven included studies, a low confidence level and a substantial inter-study variability, the results appear to be robust and we feel confident in suggesting that NIBS is a technique of interest for both short-term and sustained smoking cessation.”
The neurophysiology of smoking – and addiction in general – remains poorly understood, although research suggests that cravings may be at least partially mediated by activation of a brain region called the dorsolateral prefrontal cortex. When the researchers looked at the efficacy of NIBS specifically targeting this region, they found that the chance of a smoker remaining abstinent for three to six months increased by 4.34 times.
Even more impressively, they noted a 464 percent increase in the likelihood of quitting when NIBS was targeted toward the lateral prefrontal cortex and insula bilaterally.
“The neurophysiological mechanisms that lead to the observed therapeutic effect need to be further explored to understand the determinants in the efficacy of NIBS,” write the authors. In spite of this uncertainty, however, they insist that “in the near future, NIBS might be recognized as a promising new option for assisting individuals who wish to stop smoking.”