After adjustment for childhood trauma, cannabis use was no longer significantly associated with psychosis; childhood sexual abuse proved to be a considerably stronger predictor.
Summary
Population survey (n=7.403, Adult Psychiatric Morbidity Survey 2007); cannabis use alone not significant for psychosis diagnosis after adjustment for childhood trauma; childhood sexual trauma: OR 6,10 for psychosis; combined trauma + cannabis use: OR 7,84 — cannabis-psychosis association moderated by childhood trauma.
P
PopulationAdults from the British general population (Adult Psychiatric Morbidity Survey 2007), n=7403
I
InterventionCannabis use (self-reported)
C
ControlNo cannabis use
O
OutcomeIn the bivariate model, cannabis use was predictive of psychosis diagnosis; in the multivariate model accounting for childhood sexual trauma, the effect was attenuated and no longer statistically significant (OR not reported). Non-consensual sex in childhood was independently associated (OR 6,10); interaction childhood trauma x cannabis: OR 7,84 (caution: overarching analysis step not significant).
Confidence in the evidence
Very lowLowModerateHigh
Low
The second of four GRADE levels, the effect estimate is of limited reliability.
<h4>Background</h4>Cannabis consumption continues to be identified as a causal agent in the onset and development of psychosis. However, recent findings have shown that the effect of cannabis on psychosis may be moderated by childhood traumatic experiences.<h4>Method</h4>Using hierarchical multivariate logistic analyses the current study examined both the independent effect of cannabis consumption on psychosis diagnosis and the combined effect of cannabis consumption and childhood sexual abuse on psychosis diagnosis using data from the Adult Psychiatric Morbidity Survey 2007 (n=7403).<h4>Results</h4>Findings suggested that cannabis consumption was predictive of psychosis diagnosis in a bivariate model; however, when estimated within a multivariate model that included childhood sexual abuse, the effect of cannabis use was attenuated and was not statistically significant. The multivariate analysis revealed that those who had experienced non-consensual sex in childhood were over six times [odds ratio (OR) 6.10] more likely to have had a diagnosis of psychosis compared with those who had not experienced this trauma. There was also a significant interaction. Individuals with a history of non-consensual sexual experience and cannabis consumption were over seven times more likely (OR 7.84) to have been diagnosed with psychosis compared with those without these experiences; however, this finding must be interpreted with caution as it emerged within an overall analytical step which was non-significant.<h4>Conclusions</h4>Future studies examining the effect of cannabis consumption on psychosis should adjust analyses for childhood trauma. Childhood trauma may advance existing gene-environment conceptualisations of the cannabis-psychosis link.