Gangsterilm

Why do some people become addicted, while others do not?
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. For example:
  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 decisionmaking,   judgment, and self-control, they are especially prone to   risk-taking behaviors, including trying drugs of abuse.
    Drug Dependence & Abuse Causes
People abuse drugs for a number of different reasons.
  The most common reason why people abuse drugs is to "get high."   Adolescents and preadolescents can become involved in experimentation   with drugs. However, only a small percentage of people who   experiment with drugs become drug abusers. The desire to get   high may be from an underlying disease such as depression.   It may...