• Genetic and environmental influences modulating risk of substance use disorders change
developmentally and across the lifespan.• Genes involved in vulnerability to addictions
include both substance-specific genes and genes that act on common pathways involved in
addiction to different agents and propensity to other psychiatric disorders. Substance-
specific genes include genes for metabolic enzymes involved in the metabolism of the
substance (eg, ALDH2, ADH1B for alcohol) as well as genes encoding gatekeeper …