There is currently no treatment for fighting cannabis use disorder (CUD) in patients with schizophrenia. But that may soon change as a new study suggests that repetitive transcranial magnetic stimulation (rTMS) has the potential to help reduce cannabis use.
Until in recent years, rTMS and other brain stimulation technologies were mainly used for tackling depression cases that are hard to treat. Newer research has now shown that they could also be useful for dealing with varied substance use disorders.
In the current study, scientists observed that rTMS led to a significant drop in self-reported use of cannabis. The double-blind inquiry is the first to explore the possible efficacy of brain stimulation technology for CUD treatment in people with schizophrenia.
The study, published in Schizophrenia, was led by researchers from The Centre for Addiction and Mental Health (CAMH) in Canada.
“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 Dr. Tony George, a clinician-scientist at CAMH. “These results indicate rTMS may be a safe and effective way to reduce cannabis use among people with schizophrenia.”
A reason for the lack of CUD treatment
For now, there is no approved remedy for CUD in people with or without schizophrenia.
However, in the case of those with schizophrenia, researchers say that the lack of treatment is partly because people with such mental illnesses are typically not included in CUD trials.
Dr. George said CAMH was in a better position to carry out this sort of research, being one of the leading mental health teaching hospitals in the world.
“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,” he said. “All those factors make CAMH one of the few places in the world that can lead a study like this.”
Regardless of the status of the hospital, researchers noted that it was still not easy to get subjects for the study. This was because of the amount of time that would be involved.
The team, however, managed to get a number of patients that were notably high enough. These people showed awareness of the harmful effects of cannabis use and desired positive outcomes from reduced use.
Brain stimulation as a treatment
The researchers came to the conclusion that rTMS may help against CUD after treating patients with it for 28 days (four weeks). They administered the treatment to subjects five times every week at CAMH’s Temerty Centre for Therapeutic Brain Intervention.
The target of this treatment is the dorsolateral prefrontal cortex (DLPFC). This part of the brain is linked to the reward system as well as executive function.
After 28 days of treatment, participants that were treated with rTMS reported using cannabis by up to 60 percent less, compared to those given fake rTMS. They also showed reduced cravings.
This research was backed by the CAMH Foundation and the U.S. National Institute on Drug Abuse (NIDA). It shows promise for the treatment of hard-to-treat CUD with noxious effects.