This new edition presents an up-to-date, comprehensive overview of the GABAB receptor system, including a particular focus on the most recent therapeutic applications and potential. This receptor system has been implicated in several diseases and disorders, including gastroesophageal reflux disease, epilepsy, mood disorders, depression, and alcohol and substance use disorder. The authors, leading researchers in the field, explore a number of approaches, including medicinal chemistry, molecular biology, physiology, and preclinical and clinical pharmacology. The new edition is completely reworked and updated, featuring the latest pharmacological advances on baclofen and positive allosteric modulators.