Brief and acute psychotic disorders with a short duration and a generally good prognosis have long intrigued psychiatrists. Although they are included in internationally accepted diagnostic systems, understanding of these disorders remains minimal. This book is the first comprehensive overview of the clinical features, biology, course and long-term outcome of brief and acute psychoses. The authors review the world literature on the topic and they also present data from their own longitudinal study - the most complete investigation of this group of disorders so far conducted. The book concludes with considerations of the nosological status of brief and acute psychoses and their impact on our understanding of the continuum of psychotic and affective disorders.