Chapter 2 explores the neurobiology of addiction (new to this edition): "the loss of control over drug use, or the compulsive seeking and taking of drugs despite adverse consequences." It focuses on sensitization: "enhanced drug responsiveness with repeated exposure to a constant dose." In this chapter the author reviews animal models, neuroanatomy, neurotransmitters, neuromodulaters, intracellular signaling, and rewards systems to explain behaviors. Chapters 3 to 13 are each dedicated to a single substance of abuse, including opioids, cocaine, anticholinergics, ethanol, and tobacco. Each chapter provides exhaustive knowledge on aspects of the particular substance of abuse such as origin, availability, receptor effects, addiction, withdrawal, fetal effects, organ damage, and treatment. The author also discusses public policy on individual drugs.