The association betweeen cannabis use and psychosis
Researchers from Australia report that early use of marijuana is a risk-modifying factor for psychosis in young adults.
First, the details.
- 3801 young adults born between 1981 and 1984 were followed for 21 years.
- Marijuana use and 3 psychosis-related outcomes (nonaffective psychosis, hallucinations, and Peters et al Delusions Inventory score) during that time were compared.
- Nonaffective psychosis refers to psychosis not related to emotions or moods
- The Peters et al Delusions Inventory includes measures of distress, preoccupation, and conviction.
- Associations between duration since first cannabis use and psychosis-related outcomes were adjusted for gender, age, parental mental illness, and hallucinations at the 14-year follow-up.
- There were 228 siblings in the group who were also compared.
And, the results.
- The duration since first cannabis use was associated with nonaffective psychosis, hallucinations, and Peters et al Delusions Inventory score.
- For those who smoked pot for at least 6 years, there was a significantly increased risk of nonaffective psychosis in those who smoked the most based on the Peters et al Delusions Inventory score, and in hallucinations.
- Within sibling pairs, there was a significant association between the duration since first cannabis use and higher scores on the Peters et al Delusions Inventory.
The bottom line?
The authors concluded, “Early cannabis use is associated with psychosis-related outcomes in young adults.”
The sibling pairs data reduce the likelihood that confounding factors might explains these findings.
It’s dangerous and there’s scant support for its use based on medical science.
3/17/10 20:36 JR