In this paper, the author reports on a Paris conference attended by medical practitioners and pharmaceutical scientists from nine countries, including Ireland. The conference was organised by Professor Gabriel Nahas of Columbia University, New York, and scientific advisor to EURAD (Europe against Drugs). The meeting was divided into three sessions dealing with cannabis, cocaine and crack, and opiates. It was designed to give a European audience an update on recent studies of the damaging effects of the three groups of drugs on the human body.