What is the Link Between Cannabis and Psychiatric Diagnoses?

Mark Viner, MD, is a psychiatrist based in Reno, Nevada and has extensive experience in schizophrenia, Clozapine, psychopharmacology, and suicide research. He is an active member of organizations focused on cannabis medicine, including the Clinical Society of Cannabis Clinicians and the International Alliance of Medicinal Cannabinoids.

In a video interview with Psychiatric Times, Viner said 1 of the most debated topics in psychiatry is the relationship between cannabis and schizophrenia. Both conditions peak in prevalence around the same age—between ages 22 and 25. This simultaneous onset makes it difficult to establish a clear cause-and-effect relationship. He also noted that both cannabis use disorder and schizophrenia share chromosomal loci, suggesting a deeper genetic link that warrants further investigation.

Unlike hallucinogens, which do not share this genetic or temporal overlap with schizophrenia, cannabis has unique interactions with psychiatric disorders. Viner believes that further research should focus on the role of cannabis in dissociative disorders, particularly in relation to PTSD and trauma. Since cannabis can induce mild dissociation, understanding its potential therapeutic applications for trauma-related conditions could be valuable.

Beyond PTSD, he emphasized that cannabis interacts with key brain regions, such as the hypothalamus and basal ganglia, which are heavily involved in regulating sleep, appetite, and motor functions. As a result, he sees potential for cannabis-based treatments in a wide range of psychiatric and neurological disorders, including sleep disorders, feeding and eating disorders, sexual dysfunction, and elimination disorders.

He shared research on cannabis and motor disorders, particularly tic disorders and catatonia. He stressed that the motor-related effects of cannabis are not widely recognized but could offer new treatment pathways for conditions with significant movement-related symptoms.

This is part 3 of a multipart series. Parts 1 and 2 are posted to the Psychiatric Times website.

Dr Viner is a practicing physician who has been working with psychiatric patients in the state of Nevada for over 25 years. He served as a clinical professor of psychiatry and behavioral sciences at the University of Nevada School of Medicine.