NCJ Number
207599
Journal
Addiction Volume: 99 Issue: 10 Dated: October 2004 Pages: 1333-1341
Date Published
October 2004
Length
9 pages
Annotation
This study examined whether and how cannabis use in early adolescence contributes to subclinical positive and negative symptoms of psychosis.
Abstract
A cross-sectional survey in the context of an ongoing cohort study involved 3,500 19-year-olds in Greece. Participants completed the Community Assessment of Psychic Experiences, which measures subclinical positive (paranoia, hallucinations, grandiosity, and first-rank symptoms) and negative psychosis dimensions, along with depression. Drug use was also measured. The frequency of cannabis lifetime frequency use was 6 percent (n=200); once, 2 percent (n=70); 2 to 4 times, 1.4 percent (n=48); 5 times or more, 1.5 percent (n=51); and systematic use, 0.9 percent (n=31). The study found that cannabis use was significantly linked to both positive and negative dimensions of psychosis, independent of one another, and depression; however, the association of cannabis use with depression disappeared after adjusting for the negative psychosis dimensions. First cannabis use before age 16 was associated with a much stronger effect on psychosis than first use after age 15, independent of lifetime frequency of use. The association between cannabis and psychosis was not affected by the distress related to the experiences, suggesting that self-medication may not completely explain the link between cannabis and psychosis. 4 tables and 38 references