Written by two scholars with outstanding reputations in the drugs field, this book assessed current knowledge on very controversial topics: the health, psychological, and social effects of cannabis use and misuse, the effectiveness and costs of cannabis prohibition, and policy alternatives. Well written and well organised, with chapter summaries and a final topic by topic summing up, this book is probably the most comprehensive and honest attempt to improve the quality of public policy debate on cannabis.

The most comprehensive, because the authors address the whole range of relevant issues, including some that remain “taboo” in several developed countries: they compare the health effects of cannabis with alcohol and tobacco; they investigate the possible benefits of cannabis use; they scrutinise the necessary conditions to implement the legalisation of cannabis… Then “drug warriors” should be interested in reading about topics they usually refuse to discuss. For example, the authors showed very convincingly that in a legal market the government should regulate the quality, potency, price, and bulk of cannabis that is sold to consumers, so the removal of criminal sanctions for sale and possession of cannabis would not eliminate the costs of enforcing cannabis laws.

The most honest, because unlike propagandists from both sides and other self proclaimed “experts” who are prompt to express great certainty about studies flawed by methodological shortcomings, the authors admit that many results remain uncertain and controversial, and they identify promising avenues for future research. With regard to honesty, they also mention the frequent dishonest and selective citation of evidence on the health effects of cannabis that blurs the public debate and discredits health education among the youth. Last but not least, they remind us that beyond scientific evidence deciding which policy to adopt remains a moral issue depending on which social values we defend.