Recognizing marijuana is here to stay, the book provides reliable information about marijuana's effects on people. The authors recognize that marijuana policies and personal decisions about marijuana use should be based on scientific evidence, factual information, and common sense. The review of claims about marijuana and the latest scientific evidence about marijuana's effects leads the authors to conclude that, while heavy marijuana use can be harmful, marijuana use in general is not nearly as harmful as the myths about marijuana claim. Despite the criminalization of marijuana and the massive efforts embodied by the war on drugs, more adolescents have been trying marijuana in recent years. This trend should encourage alternative drug policies to effectively deal with marijuana use. Detailed information is presented on the effects of marijuana in terms of memory and cognition, deviance and crime, sex hormones and reproduction, pregnancy, the immune system, smoking and the lungs, persistence in the body, highway safety, hospital emergencies, potency, and the prevention of marijuana use. References and notes