psychotic disorder
any of a number of severe mental disorders, regardless of etiology, characterized by gross impairment in reality testing. The accuracy of perceptions and thoughts is incorrectly evaluated, and incorrect inferences are made about external reality, even in the face of contrary evidence. Specific symptoms indicative of psychotic disorders are delusions, hallucinations, and markedly disorganized speech, thought, or behavior; individuals may have little or no insight into their symptoms. Some examples of psychotic disorders are schizophrenia, schizophreniform disorder, schizoaffective disorder, delusional disorder, brief psychotic disorder, and psychotic disorders due to a substance (see substance-induced psychotic disorder) or to a medical condition.