Substance abuse involves the use of drugs, alcohol or other chemicals in a way that interferes with normal healthy functioning. Substance abuse cuts across all lines of race, culture, educational and socioeconomic status. Substance abuse is an enormous public health problem, with far-ranging effects. In addition to the health problems substance abuse can cuase, it is also considered to be an important factor in a wide variety of social problems, affecting rates of crime, domestic violence, sexually transmitted diseases (including HIV/AIDS), unemployment, homelessness, teen pregnancy, and failure in school. One study estimated that 20% of the total yearly cost of health care in the United States is spent on the effects of drug and alcohol abuse.

A wide range of substances can be abused. The most common classes include:

• Opioids (including such prescription pain killers as morphine and demerol, as well as...