This book is written for the clinician who cares for adult patients with organic mental disease-with dysfunction of the brain producing mental symptoms. It should be read from cover to cover in order to get an overview of the field, if this misshapen mass of art, knowledge, tradition, and myth can be called a field. Since organic mental patients, often depressed themselves, sometimes induce depression in their physicians, I have inter­ spersed a few amusing anecdotes and outrageous analogies to raise morale. This book is not intended to be a step-by-step cookbook, but rather to discuss principles which each practitioner can adapt to his own patient population. Nor is it intended to be an encyclopedic reference work, although sufficient quotation to the medical literature should permit the interested reader to plunge to whatever depth he desires. The present editorial custom in the United States requires combined male and female pronouns. According to this fad, the previous paragraph should have ended "he or she desires" or "hel she desires. " With a few exceptions, men and women suffer organic mental disease with equal frequency and equal severity, therefore all male pronouns and adjectives used in this book are intended to be neuter. When I refer to the patient's spouse as "his wife," please imagine that half the time it reads "her husband. " The author thanks his excellent typists, Beth Gehrke and Elizabeth Jaeckle.