Effectiveness of Transcranial Magnetic Stimulation (TMS) in Smoking Cessation, Combining Withdrawal Stimulation Followed by Maintenance Stimulation to Prevent Relapse

Brain imaging research shows that the dorsolateral prefrontal cortex (DLPC) is involved in tobacco addiction. Disorders induced in the DLPC cause an irrepressible urge to smoke (craving) and largely explain relapse during smoking cessation.

Transcranial Magnetic Stimulation (TMS) could be a promising tool in the quest for an effective approach to smoking cessation. This technique is used for direct stimulation of the DLPC via a magnetic coil in order to reduce the cortical activity of the DLPC and thus to reduce cravings.

A first randomized controlled study using TMS was conducted at the University Hospital of Dijon in highly addicted smokers who had failed to quit with the usual withdrawal strategies. In this study, entitled Tabacstim 1, we found that the combination of nicotine substitutes (to reduce physical withdrawal symptoms) with 10 "attack" sessions of TMS (to reduce cravings) increased the rate of abstinence during the first 2 weeks of withdrawal (% abstinence = 88. However, in this study, the therapeutic effect of the nicotine-SMT combination was not prolonged once the stimuli were stopped. At 6 and 12 weeks from the start of withdrawal, abstinence rates in the active SMT and placebo SMT groups were no longer significantly different.

We therefore initiated a new study, entitled Tabacstim 2, to add maintenance brain stimulation to the Tabacstim 1 protocol after the "attack" sessions (this therapeutic scheme is classically used in the treatment of depression with TMS). This study started in July 2020 and will end very soon (71 inclusions completed out of the 78 expected).

In both Tabacstim 1 and Tabacstim 2, the stimulations are delivered at low frequency (1 Hz) on the right DLPC. However, a recently published meta-analysis shows that, in addictions, stimulations delivered at a high frequency (10 Hz) on the left DLPC appear to be more effective in reducing craving. But above all, another meta-analysis carried out by our team (in progress of publication), finds that excitatory stimulations (such as 10 Hz rTMS) on the left DLPC are very effective in maintaining smoking abstinence in the medium term (3 and 6 months), which does not seem to be the case for inhibitory stimulations (such as 1 Hz rTMS).

We therefore wish to carry out the Tabacstim 3 study, which only differs from Tabacstim 2 in two stimulation parameters: 10 Hz stimulations on the left DLPC instead of 1 Hz stimulations on the right DLPC. We therefore propose in Tabacstim 3 to use excitatory stimulations on the left instead of inhibitory stimulations on the right.

Tabacstim 3 could be more effective for prolonged smoking cessation than the 2 previous protocols.