This book is the result of a study on drugs carried out by Bernard Roques at the request of the French Secretary of State for Health, Bernard Kouchner. The author has reviewed and summarised a large body of information from all over the world, so this is a thorough, detailed scientific examination of what is known today of the potential dangers, particularly for the brain, of toxic and psychotropic drugs ? including alcohol and tobacco ? which are often associated with the consumption of other drugs.This book includes an excellent explanation of the neurochemistry of dependence, in which the sum of contemporary knowledge on the workings of addiction is examined. The author goes on to give a detailed analyses of the effects of many drugs: cannabis, opiates, cocaine, ecstasy, alcohol, tobacco, psychotropic medication, etc. He then classifies the drugs into three categories, according to the gravity of the health hazard they pose. The first group comprises heroine, cocaine and alcohol; the second includes psychostimulants, hallucinogens, tobacco, benzodiazepines (anti-anxiety and hypnotic medicine); while cannabis, regarded as much less dangerous, is relegated to the thied group. Roques? study will doubtless play a major role in public health discussions and decisions, particularly in the fight against alcoholI'm and nicotine addiction. It will also provide a powerful argument for the legalisation of soft drugs. Bernard Roques is a member of the French Académie des Sciences. He teaches organic chemistry at the University of Paris-V and heads a research unit specialising in pharmaco-chemistry, at the Centre National de la Recherche Scientifique.