Vasopressin and oxytocin are the key hormones of the hypothalamo-neurohypophysial system, and are well-known to be critically involved in antidiuresis, labor, and milk ejection. This book highlights the latest research on vasopressin and oxytocin, covering multiple biological aspects. The capacity of both hormones to regulate various aspects of social behaviours including pair-bonding, aggression, maternal love, and sexual behaviour, is a main focus, as are their interactions with a variety of other neuromodulators and transmitters. Moreover, the book illustrates the recent development of vasopressin and oxytocin agonists/antagonists as potential drugs to treat not only disturbances of body fluid homeostasis, but also mental disorders, including social phobia, autism, anxiety, and depression. The promising combination of basic and clinical research, comprising physiology, neuroendocrinology, behavioral biology, pharmacology, imaging and molecular genetics makes this book an essential addition to both experts and scientists new to the field alike.