Catatonia is a syndrome of motor dysregulation found in as many as 10% of acutely ill psychiatric in-patients. Treatments are well defined and catatonia has an excellent prognosis when they are used. Two leading neuropsychiatrists describe the features of catatonia, teach the reader how to identify and treat the syndrome successfully, and describe its neurobiology. Patient case histories from the authors' clinical practices, as well as from classical literature, illustrate the principles of diagnosing and treating patients.