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Definition: mental illness from Collins English Dictionary


1 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

Summary Article: Mental Illness
From The Encyclopedia of Positive Psychology

The term mental illness refers to severe emotional or thought disturbance that negatively affects one’s health and safety. It is a collective term for all of the diagnosable mental disorders. Those with any of the severe mental disorders present with disturbances of thought and perception, dysregulation of mood, excessive and inappropriate anxiety, and/or cognitive abnormalities. People with disorders such as schizophrenia may be viewed as experiencing serious mental illness, but other disorders are best considered to have symptoms which occur on a continuum of severity. Mental disorders are a relatively common occurrence; in a given year an estimated one in four American adults experiences a diagnosable mental disorder. Serious mental illness is concentrated on a smaller group, approximately 6% of the US population. Many individuals suffer from more than one mental disorder at a time, with nearly half of those with a mental disorder meeting criteria for two or more disorders. Mental disorders often demonstrate an onset of symptoms by adolescence, with half of lifetime cases of mental illness beginning by 14 years of age, although many do not seek treatment until long after the first onset of symptoms. Untreated mental illness can lead to more severe, more difficult to treat illness, and the development of cooccurring mental illness.

The Diagnostic and Statistical Manual of Mental Disorders, fourth edition, consists of a classification of mental disorders which are conceptualized as clinically significant behavior or psychological syndromes associated with distress, disability, and impairment in functioning. Schizophrenia and other psychotic disorders include prominent psychotic symptoms which include positive symptoms such as delusions, hallucinations, and disorganized speech/behavior. There may also be negative symptoms which involve deficits such as flat affect, anhedonia, or a lack of motivation or initiative. Disturbances of mood involve sustained feelings of sadness and/or a sustained elevation of mood. Such symptoms correspond to diagnoses of either a depressive or bipolar disorder. Anxiety disorders are characterized by excessive fear in response to a threatening event and may include symptoms such as panic attacks (i.e., a sudden, discrete episode of an extreme anxiety reaction) or agoraphobia (i.e., avoidance of different places or situations). Specific diagnoses include specific phobias, generalized anxiety disorder, obsessive-compulsive disorder, post-traumatic stress disorder, and panic disorder. Somatoform disorders include the presence of physical symptoms that suggest a general medical condition and are not fully explained by a general medical condition, by the side effects of a substance, or another mental disorder. It is not intentional or under one’s voluntary control. Factitious disorder consists of physical or psychological symptoms intentionally produced or feigned to allow one to assume a sick role. Mental disorders may be diagnosed by a mental health professional through the use of clinical assessment techniques such as clinical interview (which may include some form of mental status examination), behavioral observation and assessment, and psychological testing (such as projective testing, personality inventories, and intelligence testing).

The U.S. Surgeon General released a report on mental illness in 1999 which emphasized the importance of treatment and the need for increased public awareness to decrease the stigma associated with mental illness and encourage individuals to seek treatment when necessary. Those with mental illness must deal with the disability itself, as well as negative public reaction and social stigma which may affect opportunities for work and achievement of goals. The stigma often prevents people from seeking needed treatment. Laws such as the Americans with Disabilities Act have helped, as well as an increased understanding of mental disorders and recognition of the need for treatment. Roughly one-third of individuals with mental illness receive adequate treatment, while many receive no treatment at all. Beyond medication, there is increasing recognition of a need for rehabilitative and recoveryoriented services for those with serious mental illness, including the development of evidence-based treatments which would allow individuals to gain the skills need to live productively in the community. Therapeutic approaches to treatment of mental disorders include psychodynamic, interpersonal, and cognitive-behavioral approaches. Many members of racial and ethnic minority groups are underserved by the mental health services system, thus there is a need for linguistically and culturally competent services to provide treatment for individuals from different cultural groups. The etiology or causes of mental illness are not completely known, but thought to be shaped by biological, psychological, and social/cultural factors (and the interaction among each). This biopsychosocial model of disease provides a framework for understanding health and disease which takes into account the interaction among each of those factors.

SEE ALSO: ▸ Abnormal psychology ▸ Diagnostic and Statistical Manual ▸ Mental health ▸ Psychopathology

Stephanie E. Petersen
Private practice, Houston, Texas
© 2009 Blackwell Publishing Ltd

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