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sleep disorder

a persistent disturbance of typical sleep patterns (including the amount, quality, and timing of sleep) or the chronic occurrence of abnormal events or behavior during sleep. In DSM–IV–TR, sleep disorders are broadly classified according to apparent cause, which may be endogenous or conditioning factors (primary sleep disorders), another mental disorder, a medical condition, or substance use. Primary sleep disorders are subdivided into dyssomnias and parasomnias. DSM–5, which encompasses sleep disturbances under the rubric sleep–wake disorders, eliminates sleep disorders related to another mental disorder and to a general medical condition as distinct entities in order to avoid making causal assumptions about comorbid disorders. A classification system introduced in 1979 by the Association of Sleep Disorders Centers groups sleep disorders according to individuals’ presenting symptoms: disorders of initiating and maintaining sleep; disorders of excessive somnolence; disorders of the sleep–wake cycle schedule; and dysfunctions associated with sleep, sleep stages, or partial arousals.

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Psychology term of the day

January 23rd 2025

antipsychotic

antipsychotic

n. any pharmacological agent used to control the symptoms of schizophrenia and other disorders characterized by impaired reality testing, as evidenced by severely disorganized thought, speech, and behavior. Formerly called major tranquilizers and later neuroleptics, antipsychotics are commonly divided into two major classes: conventional or typical (first-generation) antipsychotics, which were developed in the 1950s and include the phenothiazines and butyrophenones, and the newer atypical (novel or second-generation) antipsychotics, of which clozapine is the prototype, first marketed in the United States in 1990. The latter class has fewer adverse side effects than the former, particularly the neurologically based extrapyramidal symptoms but also the less serious yet unpleasant autonomic effects, such as dry mouth and blurred vision. However, the newer drugs have been associated with some serious metabolic and other effects (see atypical antipsychotic).