- any of the various forms of psychosis or severe neurosis.
- law (in England, according to the Mental Health Act 1983) mental illness, arrested or incomplete development of mind, psychopathic disorder, or any other disorder or disability of the mind
- any of various disorders in which a person’s thoughts, emotions, or behaviour are so abnormal as to cause suffering to himself, herself, or other people
- mental illness
- Any of various psychiatric conditions, usually characterized by impairment of an individual’s normal cognitive, emotional, or behavioral functioning, and caused by physiological or psychosocial factors.mental disease mental disorder
- Any of various psychiatric disorders or diseases, usually characterized by impairment of thought, mood, or behavior.