We’re arguably in a renaissance era of sorts surrounding cannabis and its medical potential, with more and more research showing the multitude of benefits this plant can offer our bodies. Even with all the good, there’s also plenty of research cautioning folks before they dive into the cannabis world.
Now, a new study nods to both sides of the coin, providing a bit of hope for those suffering from schizophrenia and cannabis use disorder (CUD).
The study, published in the journal NPJ Schizophrenia, led by the Centre for Addiction and Mental Health (CAMH) found the repetitive transcranial magnetic stimulation (rTMS) is related to a reduction in self-reported cannabis use by up to 60 percent in people with schizophrenia who had cannabis use disorder.
Brain stimulation technologies were used for treatment-resistant depression until recently, but new studies revealed the potential for rTMS in treating drug use cravings for several substances among the general population.
According to Science Daily, the double-blind study is the first of its kind to investigate the effectiveness of rTMS in treating CUD in people with schizophrenia. CUD is caused by chronic cannabis use, which causes cannabis withdrawal symptoms that come from developing dependency. Withdrawal symptoms can include anxiety, poor mood, agitation and sleep problems.
The relationship between CUD and schizophrenia has limited research behind it, though there’s shown to be a link between the two. The study’s senior author, CAMH clinician scientist Dr. Tony George, said that people with schizophrenia have “very high rates” of cannabis use disorder compared to the general population, and there is strong evidence that cannabis use can worsen psychiatric symptoms and quality of life in those people.
One 2021 study from Denmark published in JAMA Psychiatry noted the increase in schizophrenia cases linked to problematic cannabis use over the past 25 years. It looked at data from 1995, which showed just two percent of schizophrenia diagnoses around the country were associated with CUD, to 2010, where the figure had increased to eight percent.
“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 among people with schizophrenia,” George said.
The authors said that one reason there is currently no effective treatment for CUD in people with schizophrenia is because people with schizophrenia and other mental illnesses are usually excluded from CUD trials.
Study participants were given rTMS treatment at the Temerty Centre for Therapeutic Brain Intervention at CAMH five times a week for four weeks. The treatment targets the brain’s dorsolateral prefrontal cortex, which is associated with the brain’s reward system and executive function. Those who were given rTMS reported a reduction in cannabis use by up to 60 percent after 28 days along with reduced cravings.
George said that CAMH is uniquely positioned to do this kind of research, as it has one of the largest schizophrenia outpatient clinics in North America, along with state-of-the-art addiction treatment programs. George said these factors “make CAMH one of the few places in the world that can lead a study like this.”
Lead author Dr. Karolina Kozak Bidzinski added that it was challenging to recruit participants for the study given the time commitment required by each patient. Though, the potential rewards allowed researchers to complete the study with enough participants.
“The awareness patients had of the negative effects cannabis was having on their lives, the expected benefits of reducing their use and noticing the various positive outcomes that would surface throughout the duration of the trial, enabled such a high number of patients to complete the study,” Bidzinski said. “Hopefully this work paves the way for more research into investigating the effects of rTMS as a treatment for cannabis use disorder in people with schizophrenia.”
