• A group of severe mental disorders in which a person has trouble telling the difference between real and unreal experiences, thinking logically, having normal emotional responses to others, and behaving normally in social situations. Symptoms include seeing, hearing, feeling things that are not there, having false ideas about what is taking place or who one is, nonsense speech, unusual behavior, lack of emotion, and social withdrawal.
  • A major psychotic disorder characterized by abnormalities in the perception or expression of reality. It affects the cognitive and psychomotor functions. Common clinical signs and symptoms include delusions, hallucinations, disorganized thinking, and retreat from reality.
  • A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, hallucinations, emotional disharmony, and regressive behavior.
  • Class of psychoses with disturbance mainly of cognition (content and form of thought, perception, sense of self versus external world, volition) and psychomotor function, rather than affect.
  • Schizophrenia is a severe, lifelong brain disorder. People who have it may hear voices, see things that aren't there or believe that others are reading or controlling their minds. In men, symptoms usually start in the late teens and early 20s. They include hallucinations, or seeing things, and delusions such as hearing voices. For women, they start in the mid-20s to early 30s. Other symptoms include
    • unusual thoughts or perceptions
    • disorders of movement
    • difficulty speaking and expressing emotion
    • problems with attention, memory and organization
    no one is sure what causes schizophrenia, but your genetic makeup and brain chemistry probably play a role. Medicines can relieve many of the symptoms, but it can take several tries before you find the right drug. You can reduce relapses by staying on your medicine for as long as your doctor recommends. With treatment, many people improve enough to lead satisfying lives. nih: national institute of mental health