Diagnostic criteria: The main feature of the patient is severe memory impairment, not only the formation of new memory impairment (prograde amnesia), but also impairment of past memory (retrograde amnesia). Because the most severe impairment of proximal memory is present, patients often have time, place, and orientation impairment. Patients have relatively intact distant memory. Patients often refuse to acknowledge their memory deficits and put them aside. Patients are emotionally and behaviorally unresponsive. Hypochondriasis is also the earliest prominent typical manifestation. Korsakov syndrome must be distinguished from organic syndromes in which memory impairment is the prominent manifestation (e.g., dementia or delirium). The main point of differentiation is that in patients with dementia, the mental deficits are not limited to memory, but other intelligences are also impaired, in addition to personality decline. Korsakoff’s syndrome has no impairment of consciousness. It must also be distinguished from dissociative amnesia, which is usually accompanied by retrograde amnesia, except that dissociative amnesia can be modified by hypnosis or catharsis.