Since the late 1980s, researchers working worldwide have found that marijuana users have increased risk of experiencing psychosis, including schizophrenia. Now researchers reporting in the journal Molecular Psychiatry report that “our findings strongly support the large body of evidence from observational studies that exposure to cannabis plays a causal role in the development of schizophrenia.”
We hope you will review the full study, published here online.
Mol Psychiatry. 2017 Jan 24. doi: 10.1038/mp.2016.252. [Epub ahead of print] Cannabis use and risk of schizophrenia: a Mendelian randomization study.
Vaucher J1, Keating BJ2, Lasserre AM3, Gan W4,5, Lyall DM6, Ward J6, Smith DJ6, Pell JP6, Sattar N7, Paré G8,9,10,11, Holmes MV12,13.
We also invite you to review a case study reported by a physician affiliated with Columbia University’s Department of Psychiatry, College of Physicians and Surgeons, Columbia University Medical Center in New York. That case study, published Feb. 2, states in part: “… Several first-time, nonchronic cannabis users have presented to our clinic with psychosis or thought disorders lasting months after first- or second-time cannabis use.”
What is psychosis?
Dr. Christian Thurstone, an associate professor at the University of Colorado and medical director of one of that that’s largest adolescent addiction-treatment programs explains:
“Psychosis is a medical term that describes auditory and visual hallucinations. Simply put, people who are psychotic are delusional. They may see or hear things that aren’t real. Their minds often play terrible tricks on them that surface as extreme paranoia and anxiety. There are different psychotic disorders, but people tend to be most familiar with schizophrenia — which is one of the most emotionally difficult diagnoses for me to deliver to young people and their families.
“The first study revealing the link between adolescent marijuana use and the development of psychosis in early adulthood was released in Sweden in 1988. Since then, six other large studies have been conducted. Like that first Swedish investigation, they have shown a two-to-four-fold increase in the development of psychosis in young adults who used marijuana during adolescence. These studies have controlled for more than 60 variables, including gender, family history of psychosis, pre-existence of psychosis and the use of other substances along with marijuana. All of these studies have reinforced the relationship between adolescent marijuana use and the development of psychosis.”