In this comprehensive book the authors examine the health effects of each of the major illicit drugs. All the major drug classes are covered: psychostimulants, opioids, cannabis, hallucinogens and 'novel psychoactive substances'. Each chapter presents the epidemiology of use, user characteristics, dependence, drug toxicity, mortality, the effects upon each major organ system, and associated psychiatric morbidities. The Guide is an essential reference for medical practitioners, physicians in training, nurses, treatment providers, researchers, behavioural scientists and the interested layperson. The authors have skilfully integrated an extraordinary amount of research to produce clear, evidence-based, guidance for a wide range of health and social care interventions.