rTMS for Co-occurring Psychiatric and Substance Use Disorders: Narrative Review and Future Directions

Co-occurring substance use disorders (SUDs) are highly common in individuals with psychiatric illnesses. Individuals with comorbid psychiatric illness and SUDs may experience poorer mental health and decreased treatment efficacy. However, there are no FDA-approved treatments for co-occurring substance use and psychiatric disorders. Repetitive transcranial magnetic stimulation (rTMS), a form of non-invasive brain stimulation that uses an electromagnetic field to change brain activity and behavior, may be a promising treatment for co-occurring disorders. A comprehensive literature search of PubMed, MEDLINE, and Google Scholar databases was conducted, and records were manually reviewed to include all studies testing the effects of rTMS for co-occurring SUDs.

Eleven studies met our inclusion criteria. The majority (7/11) assessed rTMS for the treatment of schizophrenia and co-occurring substance use, and the remaining three studies assessed rTMS for the treatment of SUDs in mood and anxiety disorders. Potential neural circuitry targets for the treatment of co-occurring substance use and post-traumatic stress disorder, anxiety disorder, and bipolar disorder are discussed. We identify future directions and considerations for rTMS treatment and research. Namely, we recommend identification of novel treatment targets, the use of pragmatic treatment approaches, the evaluation of rTMS for substance withdrawal, the evaluation of state dependence as a predictor of treatment efficacy, the use of neurobiological measurements to identify underlying neural circuitry, and the assessment of individual predictors of rTMS treatment response.

There is preliminary evidence suggesting rTMS may be effective to treat co-occurring disorders, but additional research is needed.