A new study led by the Centre for Addiction and Mental Health (CAMH) provides some hope for those suffering from both schizophrenia and cannabis use disorder.
By Nina Zdinjak
Despite its long history and tradition, there still exist many unknowns when it comes to marijuana. Some claim cannabis has myriad benefits, others issue myriad warnings. What is certain is that everyone seems to have an opinion and few are indifferent on the topic.
With more and more countries around the world embracing the plant, either for medical or recreational purposes causing the industry to boom, a glaring need still persists: research.
Despite the fact that there are more studies and information available these days on marijuana and its effects on our physical and mental health, we are so far from having it all figured out — if that is even a possibility.
A new study led by the Centre for Addiction and Mental Health (CAMH) and published in the journal NPJ Schizophrenia provides some hope for those suffering from both schizophrenia and cannabis use disorder (CUD).
According to this new research, repetitive transcranial magnetic stimulation (rTMS) is related to a reduction in self-reported marijuana use by up to 60% in people with schizophrenia who have cannabis use disorder, reveals Science Daily.
First things first. What is a cannabis use disorder?
Although not often spoken about in this era of marijuana legalization, chronic cannabis use is known to have caused cannabis use disorder. The condition causes marijuana withdrawal symptoms that come from the development of dependency, and are often compared to those of nicotine withdrawal. Most common cannabis withdrawal symptoms include anxiety, poor mood, agitation and sleep problems.
What about schizophrenia? How is this mental health disorder related to cannabis? That’s when research is scant. A chronic illness that affects some 20 million people seems to have an interesting relationship with cannabis, but not everything is completely clear.
One thing though, CAMH clinician-scientist Dr. Tony George explains, “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.”
George talked about the positive results of the new study. “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.”
The double-blind study, said to be the first of its kind to examine the effectiveness of rTMS in treating CUD in people with schizophrenia, was supported by the U.S. National Institute on Drug Abuse (NIDA) and the CAMH Foundation.
Interestingly, until relatively recently brain stimulation technologies were usually used for treatment-resistant depression. Fortunately, new studies revealed the potential of rTMS in treating drug use cravings for several substances among the general population.
In this study, participants were given rTMS treatment at the Temerty Centre for Therapeutic Brain Intervention at CAMH five times a week for a month, targeting the part of the brain that controls the reward system and executive function.
Those who were given rTMS confirmed cannabis use reduction of up to 60% after 28 days and also reduced cravings as compared to the control group that received fake rTMS.
The study’s authors explained that the lack of efficient treatments for CUD in individuals with schizophrenia is because people with mental illness are commonly excluded from CUD clinical trials.
“In addition to our ability to conduct clinical trials with brain stimulation at the Temerty Centre, CAMH also has one of the largest schizophrenia outpatient clinics in North America as well as state-of-the-art addiction treatment programs,” Dr. George explained. “All those factors make CAMH one of the few places in the world that can lead a study like this.”
The study’s lead author Dr. Karolina Kozak Bidzinski, added, “It was a difficult study to recruit  given the intensity of time commitment required by patients. However, 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.”