Disorders of Cognitive Function

Abstract

Abstract The terms organic brain syndrome and dementia are applied to those acquired disorders of thinking and cognitive functions where altered structure or function of the brain can be identified. Generally, neurologists care for patients with these disorders. When no lesion or physiologic change is apparent, cognitive dysfunctions are often labeled functional or psychological disorders. Psychiatrists care for these patients. The inadequacy of this distinction is immediately apparent: any change in behavior must be the result of altered brain activity. In 1994 DSM-IV recognized this arbitrary distinction and did away with the division of behavior disorders into organic and nonorganic conditions. The section called “Organic Disorders” in previous DSM editions is called “Delirium, Dementia, and Amnestic and Other Cognitive Disorders” in DSM-IV; this category now stands alongside Affective, Anxiety, Schizophrenic Disorders, etc., removing any implication that there is one group of disorders related to the brain and another group that is just psychological (Tucker et al., 1994). To some degree, cognitive, affective, and behavioral symptoms characterize all disorders of the brain. There are cognitive disturbances in most of the major psychiatric disorders (see Chapters 3 and 5). However, the primary symptoms of delirium, dementia, and amnestic disorders are disturbances of cognition. Cognition comes from the Latin cognitio, which means to think.