The 90 percent who use drugs or alcohol but do not become addicted also have an impact on society. The use and abuse of mood-altering drugs contribute to the overburdening of the health care, criminal justice, and educational systems. Both users and abusers have the potential for driving under the influence, overdosing, committing crimes to support their use and abuse, and contributing to family discord and violence. There has been controversy over the cause of addiction. Historically, it was thought that addiction was caused by lack of willpower, by poverty, moral weakness, mental illness, genetics, family socialization, anti-social personalities, and societal problems.
Some drugs are more addictive than others.
This is due to the pharmacology of the substance, and how it affects the mood of the user. The genetics of the user and his overall self-concept contribute to the potential for addiction. A person from a family with alcoholic or drug-addicted parents is twice as likely to develop an addiction. Studies are now being done to learn more about the genetics of addiction, and to develop early intervention programs for people who have a greater potential for becoming addicted. People who have low self-concepts, who feel bad about themselves, have a higher rate of addiction.