Results of the model show that individual differences in both cannabis withdrawal and abuse /dependence are substantially attributable to additive genetic factors (51% for withdrawal, and 68% for abuse/dependence), and the remaining variance was mainly due to unshared environmental factors. Variance in both variables overlaps greatly, due to very high genetic and environmental correlations between both variables. Of the total phenotypic variance between withdrawal and abuse/dependence, 64% is due to overlapping genetic, 8% to shared environmental, and 28% to unshared environmental influences.
