Bern, Switzerland: The use of cannabis prior to age 14 is associated with an earlier age at onset of first-episode psychosis, according to trial data published online in the journal Schizophrenia Research.
Investigators at the University Hospital of Child and Adolescent Psychiatry assessed the differences in the age at onset of psychosis among 625 patients with and without a history of cannabis use.
Researchers reported, "Only cannabis use … starting at age 14 was associated with an earlier age at onset at a small effect size." Overall, the age at onset for patients with first-episode psychosis "was not significantly different" among patients with a history of cannabis use versus non-users.
A 2010 U.S. study reported in the same journal also failed to independently associate cannabis use with an earlier age of onset of positive symptoms in first-episode schizophrenic patients. The study concluded: "Although cannabis use precedes the onset of illness in most patients, there was no significant association between onset of illness and (cannabis use) that was not accounted for by demographic and clinical variables. … Previous studies implicating cannabis use disorders in schizophrenia may need to more comprehensively assess the relationship between cannabis use disorders and schizophrenia."
For more information, please contact Paul Armentano, NORML Deputy Director, at: firstname.lastname@example.org. Full text of the study, "Cannabis use disorder and age of onset: A study in first-episode patients," appears online in the journal Schizophrenia Research.
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