Prefrontal cortex stimulation in substance use disorder: a deep TMS (dTMS) study

Abstract Substance use disorder (SUD) severely affects the well-being of the addicted individual, impairing the quality of life of family members and social surroundings. Despite being a leading cause of mortality worldwide, an effective treatment able to reduce SUD’s morbidity has not been identified yet. Recent understandings of addiction’s neural underpinnings, which have shown diffuse alterations involving prefrontal areas and subcortical structures of the brain, have opened new scenarios in therapeutic settings. Non-invasive brain stimulation techniques have been employed to modulate neural activity and influence the maladaptive behaviours linked to drug intake. In this study we explored if Deep Transcranial Magnetic Stimulation (dTMS) could stand as an innovative tool for the treatment of addiction, testing its feasibility on a sample of patients (N=10) detecting a SUD. 12 dTMS sessions were administered over 6 weeks, 3 times a week for the initial 3 weeks, and once a week for the resulting period, in an outpatient setting. An H4 coil was employed, allowing to stimulate bilaterally the prefrontal cortex (PFC) and the insula. Intensity was set at 100% of the motor threshold and frequency at 15 Hz. Measures of craving, depression, impulsiveness, general psychopathology, and quality of life were collected before and after the treatment, and 3 and 6 months after the end, as follow-ups. For each measure, a mixed model was run. Preliminary results showed significant improvements in craving scores, impulsiveness, depression, psychopathology, and overall perception of quality of life. Data from follow-ups will also provide insights about the efficacy of our protocol over a medium-term period. Our results, although still preliminary, suggest the feasibility of successfully applying dTMS within clinical settings. Once the entire sample will be collected, this study will provide powerful insights on the potential of deep brain stimulation for the recovery of addiction. Research Category and Technology and Methods Clinical Research: 10. Transcranial Magnetic Stimulation (TMS) Keywords: Transcranial Magnetic Stimulation, Substance use disorder, Prefrontal cortex