Researchers investigate the relationship between genetic risk for schizophrenia and cannabis-related experiences. A study using a sample of 4,832 individuals from the Collaborative Study on the Genetics of Alcoholism (COGA) who had a history of alcohol use disorders was conducted. The participants’ cannabis involvement, including cannabis use disorder (CUD), was measured, and their polygenic risk scores (PRS) for schizophrenia were calculated.
Previous research has shown that heavy cannabis use is linked to features of schizophrenia, including psychotic-like experiences and cognitive difficulties. There is also evidence of genetic overlap between cannabis use, schizophrenia, and susceptibility to psychotic-like experiences.
The results from the study showed that higher genetic risk for schizophrenia was associated with various cannabis-related experiences, such as paranoia, depression, social withdrawal, and cognitive difficulties, even after controlling for factors like the duration of cannabis use, CUD severity, and age at first cannabis use. The findings were further supported by a replication sample of 1,446 individuals. Therefore, the study suggests that individuals who regularly use cannabis and have a higher genetic risk for schizophrenia are more likely to report unusual experiences related to cannabis use, even if they don’t have clinical features of schizophrenia.
Johnson EC, Colbert SMC, Jeffries PW, Tillman R, Bigdeli TB, Karcher NR, Chan G, Kuperman S, Meyers JL, Nurnberger JI, Plawecki MH, Degenhardt L, Martin NG, Kamarajan C, Schuckit MA, Murray RM, Dick DM, Edenberg HJ, D’Souza DC, Di Forti M, Porjesz B, Nelson EC, Agrawal A (2023) Associations Between Cannabis Use, Polygenic Liability for Schizophrenia, and Cannabis-related Experiences in a Sample of Cannabis Users. Schizophrenia Bulletin, 49(3), 778-787. PMID: 36545904; PMCID: PMC10154717; DOI: 10.1093/schbul/sbac196.