Psychosis (from the Greek ψυχή "psyche", for mind or soul, and -ωσις "-osis", for abnormal condition), with adjective psychotic, literally means 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 suffering from psychosis are said to be psychotic.

People experiencing psychosis may report hallucinations or delusional beliefs, and may exhibit personality changes and disorganized thinking. This may be accompanied by unusual or bizarre behavior, as well as difficulty with social interaction and impairment in carrying out the activities of daily living.

A wide variety of central nervous system diseases, from both external toxins, and from internal physiologic illness, can produce symptoms of psychosis.

However, many people have unusual and distinct (unshared) experiences of what they perceive to be different realities without fitting the clinical definition of psychosis. For example, many people in the general population have experienced hallucinations related to religious or paranormal experience. These experiences may or may not meet the clinical definition of psychosis. As a result, it has been argued that psychosis is simply an extreme state of consciousness that falls beyond the norms experienced by most. In this view, people who are clinically found to be psychotic may simply be having particularly intense or distressing experiences (see schizotypy).

In contemporary culture, the term "psychotic" is often incorrectly used interchangeably with "psychopathic or sociopathic", which actually describe a propensity to engage in violently antisocial behaviors and does not usually involve hallucinations or delusions.

Signs and symptoms

People with psychosis may have one or more of the following: hallucinations, delusions, or thought disorder, as described below.

Hallucinations

Hallucination is defined as sensory perception in the absence of external stimuli. They are different from illusions, or perceptual distortions, which are the misperception of external stimuli. Hallucinations may occur in any of the five senses and take on almost any form, which may include simple sensations (such as lights, colors, tastes, and smells) to more meaningful experiences such as seeing and interacting with fully formed animals and people, hearing voices, and having complex tactile sensations.

Auditory hallucinations, particularly experiences of hearing voices, are a common and often prominent feature of psychosis. Hallucinated voices may talk about, or to, the person, and may involve several speakers with distinct personas. Auditory hallucinations tend to be particularly distressing when they are derogatory, commanding or preoccupying. However, the experience of hearing voices need not always be a negative one. Research has shown that the majority of people who hear voices are not in need of psychiatric help. The Hearing Voices Movement has subsequently been created to support voice hearers, regardless of whether they are considered to have a mental illness or not.