RTMS Dosing for Smoking Cessation: Pre-COVID Preliminary Results

Abstract

Abstract High frequency Repetitive Transcranial Magnetic Stimulation (rTMS) is a novel treatment for smoking cessation, but the optimal dosing parameters for long-term cessation are unknown. While increasing intensity and duration might improve outcomes, participant burden can negatively affect outcomes. We will present preliminary results from an ongoing study aimed to determine optimal 20Hz rTMS (110% MT) dosing of the left dorsolateral prefrontal cortex for long-term smoking cessation. We examined the effects of two dosing parameters, duration (8, 12, or 16 days of stimulation) and intensity (900 or 1800 pulses per day) on delay discounting rate (a prognostic indicator), latency to relapse, and 6-month abstinence rates among participants who received active rTMS (n=23). We also examined research burden among participants who received active and sham rTMS (n=51) using the Perceived Research Burden Assessment (PeRBA). We hypothesized that greater rTMS duration and intensity will result in lower discounting rates and greater latency to relapse, abstinence rates, and research burden. With 20% of projected enrollment included, both greater duration and intensity of rTMS resulted in lower delay discounting rates. Abstinence outcomes were clinically significant. Increasing the duration from 8 to 16 days increased the latency to relapse 4.5 fold from 17 days (SD 37.0) to 76.6 days (SD 89.3); p=.39. Increasing the intensity from 900 to 1800 pulses per day doubled the latency to relapse from 23.7 days (SD 46.5) to 48.5 days; p=.75). Increasing the intensity from 900 to 1800 pulses per day doubled the 3 month abstinence and 6 month abstinence rates, respectively from 12.5% to 28.6%, p=.36; from 18.8% to 42.9%, p=.24. No indication was found that up to 32 sessions resulted in increased perceived burden in either the active or sham conditions. Preliminary findings show promise that greater duration and intensity of rTMS will result in improved long-term smoking cessation. Keywords: smoking cessation, tobacco dependence, addiction, participant research burden