schizophrenia
n. a psychotic disorder characterized by disturbances in thinking (cognition), emotional responsiveness, and behavior, with an age of onset typically between the late teens and mid-30s. Schizophrenia was first formally described in the late 19th century by Emil Kraepelin, who named it dementia praecox; in 1908, Eugen Bleuler renamed the disorder schizophrenia (Greek, “splitting of the mind”) to characterize the disintegration of mental functions associated with what he regarded as its fundamental symptoms of abnormal thinking and affect. According to DSM–IV–TR, the characteristic disturbances must last for at least 6 months and include at least 1 month of active-phase symptoms comprising two or more of the following: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, or negative symptoms (e.g., lack of emotional responsiveness, extreme
apathy). These signs and symptoms are associated with marked social or occupational dysfunction. Some have argued (beginning with Bleuler) that disorganized thinking (see formal thought disorder; schizophrenic thinking) is the single most important feature of schizophrenia, but DSM–IV–TR and its predecessors have not emphasized this feature, at least in their formal criteria. DSM–5 retains essentially the same criteria but emphasizes that delusions, hallucinations, or disorganized speech must be among the symptoms required for diagnosis. It also eliminates the five distinct subtypes of schizophrenia previously described in DSM–IV–TR: catatonic schizophrenia, disorganized schizophrenia, paranoid schizophrenia, residual schizophrenia, and undifferentiated schizophrenia. —schizophrenic
adj.