Adversity, cannabis use and psychotic experiences: evidence of cumulative and synergistic effects
Morgan C, Reininghaus U, Reichenberg A, Frissa S; SELCoH study team, Hotopf M, Hatch SL. Adversity, cannabis use and psychotic experiences: evidence of cumulative and synergistic effects. Br J Psychiatry. 2014 Mar 13.
There is robust evidence that childhood adversity is associated with an increased risk of psychosis, but there is little research on intervening factors that might increase or decrease risk following childhood adversity. Therefore, the authors aimed to investigate main effects of, and synergy between, childhood abuse and life events and cannabis use on odds of psychotic experiences.
They found strong evidence that childhood abuse and number of life events combined synergistically to increase odds of psychotic experiences beyond the effects of each individually. There was similar, but weaker, evidence for cannabis use (past year).
These findings are consistent with the hypothesis that childhood abuse creates an enduring vulnerability to psychosis that is realised in the event of exposure to further stressors and risk factors.