No single factor can predict whether or not a person will become addicted to drugs. Risk for addiction is influenced by a person’s biology, social environment, and age or stage of development. The more risk factors an individual has, the greater the chance that taking drugs can lead to addiction. According to the National Institute on Drug Abuse, the following three risk factors are most important:

Biology – The genes that people are born with––in combination with environmental influences––account for about half of their addiction vulnerability. Additionally, gender, ethnicity, and the presence of other mental disorders may influence risk for drug abuse and addiction.

Environment – A person’s environment includes many different influences––from family and friends to socioeconomic status and quality of life in general. Factors such as peer pressure, physical and sexual abuse, stress, and parental involvement can greatly influence the course of drug abuse and addiction in a person’s life.

Development – Genetic and environmental factors interact with critical developmental stages in a person’s life to affect addiction vulnerability, and adolescents experience a double challenge. Although taking drugs at any age can lead to addiction, the earlier that drug use begins, the more likely it is to progress to more serious abuse. And because adolescents’ brains are still developing in the areas that govern decision making, judgment, and self-control, they are especially prone to risk-taking behaviors, including trying drugs of abuse.

(Adapted from: http://www.nida.nih.gov/scienceofaddiction/brain.html)