For some time now, cannabis users have been known to be at risk of developing psychosis more often than nonusers. Now though, researchers from King’s College London have found that cannabis users with a genetic predisposition to schizophrenia are especially at risk.
For the study, the researchers analyzed data from the UK Biobank, a biomedical database containing in-depth information about participants’ health and genomes. In particular, the researchers examined the relationship between genetics, cannabis use, and psychotic experiences from 109,308 people.
To do so, they looked at reports of how frequently patients used cannabis and whether they had any psychotic experiences, characterized as auditory or visual hallucinations. The researchers also scored each participant’s genetic risk for schizophrenia by looking at which of their DNA mutations were more common among those with schizophrenia than the general population.
In the end, they found that people who used cannabis were 50% more likely than nonusers to report psychotic experiences. The incidence of these experiences, however, was 60% for those with the highest genetic risk scores for schizophrenia and 40% for those with the lowest genetic risk sores.
The researchers say that their results are the first evidence that people genetically prone to psychosis may be disproportionately affected by cannabis. They added that as genetic risk scoring is still in early development, genetics may have an even more significant influence on the relationship between cannabis and psychosis than currently known.
“This study, while limited in scope, is an important step forward in understanding how cannabis use and genetics may interact to influence psychosis risk,” says Dr. Shreejoy Tripathy, senior author of the study.
“The more we know about the connection between cannabis and psychosis, the more we can inform the public about the potential risks of using this substance. This research offers a window into a future where genetics can help empower individuals to make more informed decisions about drug use.”