A mental disorder or mental illness
is a psychological or behavioral pattern that is generally associated with distress or disability, and which is not considered part of normal development or a person's culture. Such disorders are defined by a combination of affective, behavioral, cognitive or perceptual components, which may be associated with particular functions or regions of the brain or nervous system, often in a social context.
The recognition and understanding of mental health conditions have changed over time and across cultures, and there are still variations in definition, assessment and classification, although standard guideline criteria are widely used. According to the World Health Organisation (WHO), over a third of people in most countries report problems at some time in their life which meet criteria for diagnosis of one or more of the common types of mental disorder.
The causes of mental disorders are varied and in some cases unclear, and theories may incorporate findings from a range of fields. Services are based in psychiatric hospitals or in the community, and assessments are carried out by psychiatrists, clinical psychologists and sometimes psychiatric social workers, using various methods but often relying on observation and questioning. Clinical treatments are provided by various mental health professionals.
Psychotherapy and psychiatric medication are two major treatment options, as are social interventions, peer support and self-help. In a minority of cases there might be involuntary detention or involuntary treatment, where legislation allows. Stigma and discrimination can add to the suffering and disability associated with mental disorders (or with being diagnosed or judged as having a mental disorder), leading to various social movements attempting to increase understanding and challenge social exclusion.
