Mental disorder

A mental disorder or mental illness is a psychological or behavioral pattern that occurs in an individual and is thought to cause distress or disability that is not expected as part of normal development or culture. The recognition and understanding of mental disorders has changed over time and across cultures. Definitions, assessments, and classifications of mental disorders can vary, but guideline criteria listed in the ICD, DSM and other manuals are widely accepted by mental health professionals. Categories of diagnoses in these schemes may include dissociative disorders, mood disorders, anxiety disorders, psychotic disorders, eating disorders, developmental disorders, personality disorders, and many other categories. In many cases there is no single accepted or consistent cause of mental disorders, although they are often explained in terms of a diathesis-stress model and biopsychosocial model. Mental disorders have been found to be common, with over a third of people in most countries reporting sufficient criteria at some point in their life. Services for mental disorders may be based in hospitals or in the community. Mental health professionals diagnose individuals using different methodologies, often relying on case history and interview. Psychotherapy and psychiatric medication are two major treatment options, as well as supportive interventions and self-help. Treatment may be involuntary where legislation allows. Several movements campaign for changes to services and attitudes, including the Consumer/Survivor Movement. There are widespread problems with stigma and discrimination.

The state of anxiety or fear can become disordered, so that it is unusually intense or generalized over a prolonged period of time. Commonly recognized categories of anxiety disorders include specific phobia, Generalized anxiety disorder, Social Anxiety Disorder, Panic Disorder, Agoraphobia, Obsessive-Compulsive Disorder, Post-traumatic stress disorder. Relatively long lasting affective states can also become disordered. Mood disorder involving unusually intense and sustained sadness, melancholia or despair is know as Clinical depression (or Major depression), and may more generally be described as Emotional dysregulation. Milder but prolonged depression can be diagnosed as dysthymia. Bipolar disorder involves abnormally "high" or pressured mood states, known as mania or hypomania, alternating with normal or depressed mood. Whether unipolar and bipolar mood phenomena represent distinct categories of disorder, or whether they usually mix and merge together along a dimension or spectrum of mood, is under debate in the scientific literature.
Patterns of belief, language use and perception can become disordered. Psychotic disorders centrally involving this domain include Schizophrenia and Delusional disorder. Schizoaffective disorder is a category used for individuals showing aspects of both schizophrenia and affective disorders. Schizotypy is a category used for individuals showing some of the traits associated with schizophrenia but without meeting cut-off criteria.