March 2 , 2022 (Toronto) — Repetitive transcranial magnetic stimulation (rTMS) was associated with a reduction in self-reported cannabis use by up to 60 per cent among people with schizophrenia who have cannabis use disorder (CUD), according to a CAMH-led study just published in the journal Schizophrenia.
The double-blind study is the first of its kind to investigate the effectiveness of rTMS in treating CUD in people with schizophrenia, and was supported by the U.S. National Institute on Drug Abuse (NIDA) and the CAMH Foundation.
“People with schizophrenia have very high rates of cannabis use disorder compared to the general population, and there is strong evidence that cannabis use worsens psychiatric symptoms and quality of life in these people,” said senior author CAMH clinician scientist Dr. Tony George. “Despite the known harmful effects, there is currently no approved treatment for CUD with or without schizophrenia. These results indicate rTMS may be a safe and effective way to reduce cannabis use among people with schizophrenia.”
Until relatively recently, brain stimulation technologies like rTMS were used primarily for treatment-resistant depression. However, studies have now found rTMS to be effective in reducing drug use and cravings for several substance use disorders in the general population.
Study participants were given rTMS treatment at the Temerty Centre for Therapeutic Brain Intervention at CAMH five times a week for four weeks targeting the brain’s dorsolateral prefrontal cortex (DLPFC), which is associated with the brain’s reward system and executive function.