Part 1 Science and policy - general issues in a special arena: substance misuse and the uses of science, Griffith Edwards; private behaviour and public policy, Laurence E. Lynn Jr; drugs, science and policy - a view from the USA, Robin Room; discussion - games policy-makers play; science policy from a cancer research setting, Walter Bodmer; beyond the invisible college - a science policy analysis of alcohol and drug research, Thomas F. Babor; discussion - the optimum conditions for making science happen. Part 2 Prevention - science and policy connection in different substance fields: tobacco-related disease, Robert West; alcohol prevention, Reginald Smart; licit psychotropic drugs, Malcolm Lader; the US anti-drug prevention strategy - science and policy connection, Herbert Kleber; commonalities and diversities in the science and policy questions across different substances, Marcus Grant; discussion - what future for prevention? Part 3 Substance misuse - how good is science in responding to suddenly changing policy demands: the impact of AIDS on the research agenda, Gerry Stimson and John Strang; cocaine - challenges to research, Charles Schuster and Steven W. Gust; research, policy and the problems set by rapid social, economic and political change, Robin Room; action at the local level - aids to strategic thinking, David Robinson. Part 4 Science and treatment policies: the nature of the target disorder - an historical perspective, Virginia Berridge; prospects, politics and paradox - pharmacological research and its relelvance to policy development, Roger E. Meyer; psychological treatments - the research and policy connections, Ray Hodgson; implications of recent research on psychotherapy for drug abuse, Kathleen M. Carroll and Bruce J. Rounsaville; appropriate expectations for substance abuse treatments - can they be met?, A. Thomas McLellan et al; short-term views will not do for long-term problems, Anders Romelsjo; interpretation of treatment outcome research - skill or racket, D. Colin Drummond; limits to generalizability in treatment research, Marc Alan Shuckit; discussion - science and treatment, what message for the policy-maker? Part 5 The legalization debate - finding the scientific basis for productive discussion: the great legalization debates, Harold Kalant; the rise and fall of epidemics - learning from history, David F. Musto; behavioural pharmacology of addictive drugs - cost, availability and individual differences, Ian Sherman; projections of the health consequences of illicit drug use - what contribution to the legalization debate?, John Strang and Graham Medley; estimating the social and economic costs and benefits of drug policies, Dean R. Gerstein; psychological issues in drug policies as they bear on the legalization debate, Richard Jessor; discussion - research and policy connections beyond the year 2000. Part 6 A summing up: looking forward, Jerome H. Jaffe.