The adaptive changes within the central nervous system that prepare the body for the physiological requirements of pregnancy and motherhood are of major significance, and many scientists around the world are involved in elucidating these systems in humans and other mammals. The adaptive changes encompass diverse scientific disciplines, including neuroendocrinology, neuroscience and psychology; and failure of appropriate adaptation in mothers can lead to disorders that have profound and long lasting consequences for individuals and for society. This volume contains review articles written by the symposium speakers at a conference held in Bristol in July 1999 entitled: "The Maternal Brain: an International Meeting on Neurobiological and Neuroendocrine Adaptation and Disorders in Pregnancy and Postpartum". This was the first conference to address The Maternal Brain, and comprised wide ranging topics from molecular analysis of physiological systems using transgenic animals, through plasticity at the neurotransmitter and neuronal level, to the description of behavioural adaptation in terms of endocrinology, emotionality and its underlying causes, and analysis of psychosis; all in the peripartum period.