The misuse of alcohol, drugs, and tobacco poses problems of enormous international importance. Basic research is directed at the psychological, biological, and genetic basis of substance dependence, but valuable contributions also arise from the fields of social science, economics, and historical scholarship. How can the findings of this rich and diverse scientific work be used effectively by policy-makers? This book explores ways of building bridges between the scientific and policy worlds. The coverage is broad, and subjects discussed include the responsiveness of science to changing policy demands, prevention in different substance fields, treatment policies, issues of legalization, and prospects for future developments. The contributors are leading authorities from many countries, with experience in treatment work, pure and administrative research, and dialogue with government. The resulting volume presents a broad and lively debate on how science can most fruitfully influence policy-making in the field of substance abuse.