Unformatted text preview: COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. DISORDERS
PSYCHIATRIC ILLNESSES ARE OFTEN HARD TO RECOGNIZE, BUT GENETIC TESTING AND NEUROIMAGING COULD SOMEDAY BE USED TO IMPROVE DETECTION BY STEVEN E. HYMAN
ACCURATE DIAGNOSIS IS THE CORNERSTONE OF
medical care. To plan a successful treatment for a patient, a doctor must first determine the nature of the illness. In most branches of medicine, physicians can base their diagnoses on objective tests: a doctor can examine x-rays to see if a bone is broken, for example, or extract tissue samples to search for cancer cells. But for some common and serious psychiatric disorders, diagnoses are still based entirely on the patient's own report of symptoms and the doctor's observations of the patient's behavior. The human brain is so enormously complex that medical researchers have not yet been able to devise definitive tests to diagnose illnesses such as schizophrenia, autism, bipolar disorder or major depression. Because psychiatrists must employ subjective evaluations, they face the challenge of reliability: how to ensure that two different doctors arrive at the same diagnosis for the same patient. To address this concern, the American Psychiatric Association in 1980 published the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (widely known by the acronym "DSM-III"). Unlike earlier editions of the manual, DSM-III and its successor volumes (the latest one is referred to as DSM-IV-TR) describe what symptoms must be present-- and for how long-- to make a diagnosis of a particular brain disorder. Virtually all these criteria, however, are based on the patient's history and the clinical encounter. Without the ability to apply objective tests, physicians may fail to detect disorders and sometimes mistake the symptoms of one illness for another's. Making the task more difficult is the fact that some psychiatric illnesses, such as schizophrenia, may turn out to be clusters of diseases that have similar symptoms but require different treatments. In recent years, though, advances in genetics, brain imaging and basic neuroscience have promised to change the way that brain disorders are diagnosed. By correlating variations in DNA with disease risks, researchers may someday be able to determine which small differences in a patient's genetic sequence can make that person more vulnerable to schizophrenia, autism or other illnesses. And rapid developments in neuroimaging-- the noninvasive observation of a livSCIENTIFIC AMERICAN DIAGNOSING Brain disorders usually have behavioral symptoms that can be observed by a psychiatrist. But the checklist approach to diagnosis is far from perfect. www.sciam.com MELISSA SZALKOWSKI 97 COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. ing brain-- may eventually enable doctors to spot structural features or patterns of brain activity that are characteristic of certain disorde...
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This note was uploaded on 05/02/2010 for the course PSY 320 taught by Professor Na during the Spring '10 term at Suffolk.
- Spring '10