Recent pronouncements by the World Health Organization consider anxiety as an incapacitating and common pathological entity that affects millions of people worldwide. However, only about one-third of affected individuals receive proper treatment. There is a need to further research into its pathophysiology from a neurobiological perspective and to advance the development of models of this disorder and treatment strategies. Studies should ideally focus on humans, but animal models remain critical. This book presents a collection of studies that have used various animal models and procedures to study and manage anxiety at diverse levels of analysis.