Psychosis NOS definition
Psychosis NOS means “psychosis, not otherwise specified.” This means that the patient’s symptoms fit within a general diagnosis of psychosis (a severe mental disorder that involves a profound loss of contact with reality, including delusions and hallucinations), but that the evaluating physician is unable to come up with a more specific diagnosis based on the patient’s symptoms. “Rule out schizoaffective disorder” is not an official diagnosis, but rather a directive to assess the patient for symptoms of schizoaffective disorder in order to eliminate it, or “rule it out,” from the list of possible diagnoses. (Schizoaffective disorder is a disorder in which a patient exhibits symptoms of two diseases at once: (1) a mood disorder, such as depression; and (2) schizophrenia, which is a complex collection of symptoms persisting over time that include delusions, hallucinations, disorganized speech and behavior, etc. See Section III.B.1 infra for further discussion of the problems associated with “NOS” and “rule out” diagnoses.