Chunk #29 — Results — Prevalence of lifetime cannabis use, withdrawal, and abuse/dependence — Genetic analyses — The genetic and environmental influences on cannabis withdrawal
sex-limited model; difference in AIC=0.30), the A, C, and E estimates for males were 9%, 44%, and 47%, respectively, and for females 38%, 36%, and 26%, respectively. However, fixing the genetic or shared environmental correlation at 0.5 or 1 respectively (common effects sex-limitation model) did not lead to a significant deterioration of model fit, indicating no evidence for qualitative sex differences. Subsequently, we equated the A,C, and E estimates between the sexes (general ACE model), and results show no significant deterioration of model fit, indicating there were no significant magnitude differences in effects of A, C, and E on variance in cannabis withdrawal between males and females. Based on the general ACE model, estimates of the influence of A, C, and E (95% CIs) on cannabis withdrawal are 55% (0.1–81%), 12% (0–57%) and 33% (19–51%) respectively, where the A influences were just significant (p<0.05), but the C influences were not significantly different from zero (p=0.61).
