Biological psychiatry or biopsychiatry is an approach to psychiatry that aims to understand mental disorder in terms of the biological function of the nervous system. It is interdisciplinary in its approach and draws on sciences such as neuroscience, psychopharmacology, biochemistry, genetics, epigenetics and physiology to investigate the biological bases of behavior and psychopathology. Biopsychiatry is the branch of medicine which deals with the study of the biological function of the nervous system in mental disorders. There is some overlap with neurology, which focuses on disorders where gross or visible pathology of the nervous system is apparent, such as epilepsy, cerebral palsy, encephalitis, neuritis, Parkinson's disease and multiple sclerosis. There is also some overlap with neuropsychiatry, which typically deals with behavioral disturbances in the context of apparent brain disorder. In contrast biological psychiatry describes the basic principles and then delves deeper into various disorders. It is structured to follow the organisation of the DSM-IV, psychiatry's primary diagnostic and classification guide. The contributions of this field explore functional neuroanatomy, imaging, and neuropsychology and pharmacotherapeutic possibilities for depression, anxiety and mood disorders, substance abuse and eating disorders, schizophrenia and psychotic disorders, and cognitive and personality disorders. Biological psychiatry and other approaches to mental illness are not mutually exclusive, but may simply attempt to deal with the phenomena at different levels of explanation. Because of the focus on the biological function of the nervous system, however, biological psychiatry has been particularly important in developing and prescribing drug-based treatments for mental disorders. In practice, however, psychiatrists may advocate both medication and psychological therapies when treating mental illness. The therapy is more likely to be conducted by clinical psychologists, psychotherapists, occupational therapists or other mental health workers who are more specialized and trained in non-drug approaches. The history of the field extends back to the ancient Greek physician Hippocrates, but the phrase biological psychiatry was first used in peer-reviewed scientific literature in 1953. The phrase is more commonly used in the United States than in some other countries such as the UK. However the term "biological psychiatry" is sometimes used as a phrase of disparagement in controversial dispute. Scope and detailed definition Biological psychiatry is a branch of psychiatry where the focus is chiefly on researching and understanding the biological basis of major mental disorders such as unipolar and bipolar affective (mood) disorders, schizophrenia and organic mental disorders such as Alzheimer's disease. This knowledge has been