Why do some people become addicted to drugs, while others do not?
As with any other disease, vulnerability to addiction differs from person to person. In general, the more risk factors an individual has, the greater the chance that taking drugs will lead to abuse and addiction. "Protective" factors reduce a person's risk of developing addiction.
What factors determine if a person will become addicted?
No single factor determines whether a person will become addicted to drugs. The overall risk for addiction is impacted by the biological makeup of the individual - it can even be influenced by gender or ethnicity, his or her developmental stage, and the surrounding social environment (e.g., conditions at home, at school, and in the neighborhood).
Which biological factors increase risk of addiction?
Scientists estimate that genetic factors account for between 40 and 60 percent of a person's vulnerability to addiction, including the effects of environment on gene expression and function. Adolescents and individuals with mental disorders are at greater risk of drug abuse and addiction than the general population.