Substance abuse and dependence are prevalent disorders. The most recent estimates for 2002 indicate that an estimated 22 million Americans aged 12 and older are classified as having a substance use disorder (9.4 percent of the population) (OAS, 2003). Of these, 3.2 million are classified with dependence on or abuse of both alcohol and illicit drugs, 3.9 million are dependent on or abused illicit drugs but not alcohol, and 14.9 million are dependent on or abused alcohol but not illicit drugs.
Only a small proportion of people with substance use disorders obtain treatment. …
