A psychological disorder (also referred to as a mental illness, mental disorder, or psychiatric disorder) is a pattern of thought or behavior that is outside the expected norms and impairs an individual’s ability function in ordinary life in some way. Such disorders are generally defined by examining how a person feels, acts, thinks or perceives. These disorders are just one part of mental health, but they are an important part.
The causes of psychological disorders are varied and in some cases unclear. The theories often incorporate findings from a range of fields. Assessments are carried out by psychiatrists, clinical psychologists, and clinical social workers, using various methods which rely 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 legally allowed and necessary. Stigma and discrimination often 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. Prevention is now appearing in some mental health strategies.