Genetics: The Blueprint of Health and Disease

Why do some people become addicted while others don’t? Family studies that include identical twins, fraternal twins, adoptees, and siblings suggest that as much as half of a person’s risk of becoming addicted to nicotine, alcohol, or other substances depends on his or her genetic makeup. Finding the biological basis for this risk is an important avenue of research for scientists trying to solve the problem of substance use.

https://www.drugabuse.gov/publications/drugfacts/genetics-epigenetics-addiction