The range of harms to health from psychoactive substances is considered, an
d current data are presented on the health burden of alcohol, tobacco, and
illicit drugs. Four major strategies for preventing or reducing harm are di
scussed: education and persuasion, treatment, insulating use from harm, and
regulating the availability and conditions of use. Education and treatment
are necessary parts of an overall public health approach, but are not very
effective in themselves in reducing rates of harm in the population. Insul
ating use from harm and regulating availability have often proved effective
components of a public health approach.