Psychosis (from the Greek ψυχή psyche, "mind/soul", and -ωσις -osis, "abnormal condition or derangement") refers to an abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality". People with psychosis are described as psychotic. People experiencing psychosis may exhibit some personality changes and thought disorder. Depending on its severity, this may be accompanied by unusual or bizarre behavior, as well as difficulty with social interaction and impairment in carrying out daily life activities.
Psychosis (as a sign of a psychiatric disorder) is a diagnosis of exclusion. That is, a new-onset episode of psychosis is not considered a symptom of a psychiatric disorder until other relevant and known causes of psychosis are properly excluded. Medical and biological laboratory tests should exclude central nervous system diseases and injuries, diseases and injuries of other organs, psychoactive substances, toxins, and prescribed medications as causes of symptoms of psychosis before any psychiatric illness can be diagnosed. (Full article...)