French psychiatrist Jacques-Joseph Moreau hashish and mental illness 1845, same year Scientific American The first issue has been issued. In it, he explored his own experiences with narcotic cannabis at the Paris-based Club des Hatissans. Some of them were with Victor Hugo, Honore de Balzac, Charles Baudelaire and others. Two years ago, Morrow said:indescribable “The Joy of Wonderful Substances”. However, in his 1845 book, he notes in great clinical detail the parallels with psychosis when taken at high doses.
Nearly two centuries later, the possible link between cannabis use and schizophrenia continues to be intensively studied, often resulting in heated debate. A study published in the journal on May 4 psychology It provides new evidence that problematic cannabis use can lead to schizophrenia, especially for young men who are heavy users.
The study, perhaps the largest epidemiological survey ever conducted, directly focused on cannabis and psychosis issues, delving into Denmark’s health history from 1972 to 2021. In total, about 3,000 men between the ages of 21 and 30 could have been prevented if they had not developed cannabis use disorders. Equivalent prevention rates across the broad age range of 16 to 49 years were 15% for men and 4% for women.
Danish epidemiological studies do not conclusively prove a relationship between cannabis and schizophrenia, which can only be achieved through randomized controlled trials. However, this is due to the fact that marijuana use and efficacy in Denmark increased significantly from 13% in 2006 to 30% in 2016, alongside the rising diagnosis of schizophrenia. Correlation is confirmed. “While this does not prove causality, it does show that under the assumption of causality, the numbers behave exactly as they should,” said lead author of the study, Danish National Capital Region. said Carsten Hjorthøj, Associate Professor of Mental Health Services at . and the University of Copenhagen.
Gender and age-related risks were examined as researchers plunged into national health statistics. “The rate of schizophrenia attributed to cannabis use disorders, and the rate of potentially preventable schizophrenia, is much higher in men than in women, especially young men whose brains are still maturing. I understand,” says Hjorthøj. Say. “And we find that this increase has occurred over time in perfect parallel with the increased potency of cannabis.”
The size of the study could amplify its impact. Wilson M. Compton, Deputy Director of the National Institute on Drug Abuse, said: (NIDA) designed the study in collaboration with the Danish Metropolitan Mental Health Service. NIDA officials proposed an age and gender analysis after coming across previous studies by Danish hospitals investigating the relationship between cannabis and schizophrenia.
According to Compton, the Danish-funded study suggests whether adolescent male brains are at higher risk of developing marijuana-induced psychosis than female brains, or whether male cannabis exposure levels explain the difference. It raises many questions for future research as to whether it is possible.
The study will also have implications for public prevention and treatment strategies. “People are agents of themselves,” he says Hjorthøj. “They can decide for themselves. But when it comes to using cannabis, they make decisions based on good data, not out of talk that cannabis is perfectly harmless and probably something everyone should use. need to do it.
This latest study may fail to change the long-running debate around cannabis, schizophrenia, and statistical causality. Other researchers, Carl Hart of Columbia University and Charles Xer of the University of Wyoming, have previously proposed an alternative explanation for the link. It was one of a range of problem behaviors seen in susceptible young people. All behaviors that may increase the risk of failing schoolwork and being diagnosed with psychosis or other mental disorders. It is of little value to our efforts to better understand how and why it occurs,” the authors wrote.
David Nutt, Professor of Neuropsychopharmacology at Imperial College London and founder of Drug Science, a non-profit that provides information on drugs “not politically or commercially influenced”, is a Danish I call the research “interesting”. But “it also raises a lot more questions,” he adds.
Specifically, Nutt asked whether some of the cases in the study could have been misdiagnosed as schizophrenia rather than another diagnosis of cannabis-induced psychosis, another condition. increase. He wonders whether the reported lower risk figures for women suggest that cannabis may prevent schizophrenia. They pointed to factors the researchers found could confound the results, such as frequency of use and age at first use, or the lack of data on the amount of THC, the psychoactive component of cannabis, in the product. increase. they used.
The debate will undoubtedly continue. NIDA’s Compton suggests that prevention and education programs that warn about the risks of cannabis could be a way to test whether the link between cannabis and schizophrenia has any benefits. Scientifically, if we can successfully change cannabis use rates, it will validate the theory that cannabis causes schizophrenia,” he says. “Thus, one would think that reducing cannabis use would reduce the incidence of cannabis.”
Robin Murray, Professor of Psychiatric Studies and Associate Editor-in-Chief, Institute of Psychiatry, King’s College London psychology, Studies linking problematic cannabis use and schizophrenia have been criticized for being correlated. However, he says, the Danish study looks more closely at the specific factors (gender and age) involved in possible associations between drugs and disease than previous studies. “Therefore, causation is almost certain,” Murray says.
“Because no animal model of schizophrenia exists, it is currently not possible to prove a 100% clear causal link between environmental factors and schizophrenia.”
“Epidemiology has shown a link between smoking and cancer, and evidence for that came from showing that smearing tobacco tar on the skin of mice caused tumors,” says Murray. “Unfortunately, we don’t know what rodents would need to be induced to prove that cannabis can cause schizophrenia.”
