Reference Work Entry

Handbook of Clinical Psychology Competencies

pp 1009-1038

Organic Disorders

  • Karlee D. FellnerAffiliated withAlberta Hospital Edmonton
  • , John R. ReddonAffiliated withAlberta Hospital Edmonton


Organic mental disorders, in contrast to functional (i.e., psychological) disorders, have historically been defined as mental disorders that can be attributed to biological pathology. Disorders that were classified as organic mental disorders in previous editions of the DSM have been divided into three separate sections in the DSM-IV: (1) Delirium, Dementia, and Amnestic and Other Cognitive Disorders; (2) Mental Disorders Due to a General Medical Condition; and (3) Substance-Related Disorders. Organic mental disorders may be classified as either acute or chronic based on duration, abruptness on onset, and defining symptoms. Proper assessment and diagnosis of organic disorders is essential, as leaving them untreated may lead to further deterioration or premature death. The majority of organic disorders are maintained by the underlying biological cause, and therefore require medical treatment to ameliorate the condition. However, a biopsychosocial approach to treatment is required to address all symptoms, particularly as organic disorders often have affective and relational consequences as well. Psychotherapy and cognitive rehabilitation strategies have been shown to be effective with a variety of acute and chronic organic disorders. Although therapeutic interventions with chronic degenerative conditions, such as Alzheimer’s dementia, cannot produce permanent change, they can optimize the person’s functioning and increase quality of life. In other cases, such as moderately severe amnesia, memory functions that have been compromised may be recovered through neuro-rehabilitation. Each individual (i.e., case) is unique and depends not only on the physical factors involved but also on personal, relational, and contextual features. Thus, clinicians that practice with this heterogeneous population need considerable knowledge and clinical experience which should include competence in geropsychology and neuropsychology as well as rehabilitative and psychotherapeutic procedures.