Chapter 6 explores psychiatric causes of unresponsiveness, which must be differentiated from organic causes of stupor and coma. The chapter notes that several psychiatric disorders can result in psychogenic unresponsiveness. These include conversion reaction, catatonic stupor, a dissociative or “fugue” state, and factitious disorder or malingering. The chapter looks at these in turn. Various diagnostic tests are described in detail, including the electroencephalogram, magnetic resonance imaging, computed tomographic imaging, caloric testing, and the “Amytal interview.” Sections describes the diagnosis and treatment of catatonia, psychogenic seizures (which must be differentiated from epileptic seizures), and cerebellar mutism. The authors emphasize the importance of treating patients with psychiatric causes of unresponsiveness with compassion and understanding.