Summary: Non-invasive brain stimulation appears to increase the chance of sustained smoking abstinence for three to six months after quitting, compared with sham stimulation.
Source: Society for the Study of Addiction
A systematic review and meta-analysis published in the journal Addiction examined whether non-invasive brain stimulation (NIBS) helps smokers maintain abstinence in the medium term. The analysis found that NIBS modalities were associated with higher sustained abstinence rates at three to six months compared with sham stimulation.
Non-invasive brain stimulation techniques have received growing attention as potential treatments for substance-related and addictive disorders, including tobacco use disorder. While preliminary trials have suggested NIBS can reduce craving and support short-term abstinence, evidence for longer-term effectiveness has been limited and scattered.
Researchers at University Hospital Dijon (France) performed a systematic review and meta-analysis of randomized controlled trials to quantify the effect of NIBS on sustained smoking cessation. They searched major databases and clinical trial registries for randomized trials of NIBS in adult smokers attempting to quit, with follow-up periods longer than four weeks.
Seven randomized trials met the review criteria, comprising 699 participants in total. All trials included a sham stimulation control group, allowing comparison between active NIBS and placebo-like conditions. The available analysable data covered abstinence outcomes from three to six months after the quit attempt.
When the seven studies were pooled, the risk ratio (RR) for sustained abstinence with any form of NIBS compared with sham was 2.39 (95% confidence interval [CI] = 1.26–4.55), indicating that participants who received active NIBS were more than twice as likely to remain abstinent in the three- to six-month window. Statistical heterogeneity across studies was moderate (I2 = 40%).
Subgroup analyses identified larger effects for particular stimulation approaches and targets. Excitatory repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex showed a pooled RR of 4.34 (95% CI = 1.69–11.18; I2 = 0%). Likewise, deep rTMS targeting the lateral prefrontal cortex and insula bilaterally yielded a RR of 4.64 (95% CI = 1.61–13.39; I2 = 0%). These subgroup findings suggest that both the type of stimulation and the neural target influence outcomes.
The two main NIBS modalities described in the reviewed trials were transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS). tDCS delivers a low-intensity direct electrical current to the scalp via electrodes, subtly altering neuronal excitability. TMS employs magnetic pulses generated by a coil placed over the scalp; depending on pulse frequency and protocol, TMS can increase or decrease excitability in targeted cortical regions. Deep rTMS uses specialized coils to influence deeper cortical and subcortical structures.
The review authors noted several important caveats. Four of the seven included trials were judged to have a high risk of bias; overall confidence in the pooled estimates was graded as low. The relatively small number of trials and variation in stimulation protocols, treatment intensity, and participant characteristics contributed to uncertainty. Only three- to six-month follow-up data were consistently available, so long-term effectiveness beyond six months remains unclear.
Lead author Dr Benjamin Petit commented that, despite limitations including modest study numbers and between-study variability, the aggregated results were robust enough to recommend continued investigation of NIBS as an option to support smoking cessation. The team also highlighted that additional clinical trials are currently underway, which could clarify optimal stimulation parameters, treatment schedules, and subgroups most likely to benefit.
About this neurotech research news
Author: Jean O’Reilly
Source: Society for the Study of Addiction
Contact: Jean O’Reilly – Society for the Study of Addiction
Image: The image is in the public domain
Original Research: Closed access. “Non-invasive brain stimulation for smoking cessation: a systematic review and meta-analysis” by Benjamin Petit et al. Addiction
Abstract
Non-invasive brain stimulation for smoking cessation: a systematic review and meta-analysis
Background and Aims
Non-invasive brain stimulation (NIBS) methods have shown promise in treating tobacco use disorder, but their effect on sustained tobacco abstinence is not well established. This review aimed to assess the effectiveness of NIBS for long-term smoking cessation.
Methods
This systematic review and meta-analysis included randomized controlled trials identified through searches of major databases and clinical trial registries up to May 2021. Eligible studies enrolled adult smokers seeking cessation, used NIBS interventions (repetitive transcranial magnetic stimulation [rTMS] or transcranial direct current stimulation [tDCS]), included follow-up longer than four weeks, and reported abstinence outcomes. Abstinence rates in active NIBS groups were compared with sham NIBS or usual care, using intention-to-treat analyses and risk ratios as effect measures.
Results
Seven studies (n = 699) were included. All control groups received sham NIBS; usable outcome data were available from three to six months. The pooled RR for sustained abstinence with any NIBS versus sham was 2.39 (95% CI = 1.26–4.55; I2 = 40%). Subgroup analyses indicated larger effects for excitatory rTMS over the left dorsolateral prefrontal cortex (RR = 4.34; 95% CI = 1.69–11.18; I2 = 0%) and for deep rTMS targeting lateral prefrontal cortex and bilateral insula (RR = 4.64; 95% CI = 1.61–13.39; I2 = 0%). Four trials had a high risk of bias, and overall confidence in the findings was rated low.
Conclusion
Non-invasive brain stimulation may increase the likelihood of sustained smoking abstinence at three to six months after quitting when compared with sham NIBS or usual treatment, but further high-quality trials are needed to confirm efficacy, define optimal protocols, and establish longer-term benefits.