tag:blogger.com,1999:blog-7772182113499451603.post2643368421889817324..comments2024-03-27T10:50:53.692-05:00Comments on Real Psychiatry: The Real Role of Biological Tests in PsychiatryGeorge Dawson, MD, DFAPAhttp://www.blogger.com/profile/03474899831557543486noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-7772182113499451603.post-70749082437350623722013-05-26T01:36:59.066-05:002013-05-26T01:36:59.066-05:00Many thanks for your post Dr. Carroll. The missta...Many thanks for your post Dr. Carroll. The misstatements about the reliability and validity of psychiatric diagnosis associated with the release of DSM5 have been at such a high frequency that for a moment it seemed like I had slipped into an alternate universe. The A-list is certainly valid and interestingly is probably what Dr. Insel's scientists should investigate. It a curious state of affairs to consider that psychiatrists successfully treat thousands of patients with severe problems over the course of their careers. The media and some of our experts seem to be suggesting that is an entirely random process. If psychiatry really was the application of ineffective treatments to persons with diagnoses that lack validity - I am sure I would have become an Internist or a Neurosurgeon about 25 years ago.George Dawson, MD, DFAPAhttps://www.blogger.com/profile/03474899831557543486noreply@blogger.comtag:blogger.com,1999:blog-7772182113499451603.post-46143647507819247582013-05-25T18:04:04.278-05:002013-05-25T18:04:04.278-05:00Amen to what you say here, Dr. Dawson. It is a goo...Amen to what you say here, Dr. Dawson. It is a good corrective to the foot-in-mouth statements of Thomas Insel and David Kupfer about psychiatric diagnoses lacking because of the lack of laboratory tests.<br /><br />The existence of disease is not predicated on having a biological test. There are many areas in medicine where there is no conclusive diagnostic test. Think migraine. Think multiple sclerosis. We identified many diseases before lab tests came along.<br /><br />Laboratory tests are not the automatic gold standard of evidence for validity that Insel and Kupfer imply. Indeed, in many areas diagnostic tests cause clinical mischief. That’s what the whole debate around indiscriminate diagnostic screening is about. Laboratory measures are the servants of clinical science, not the other way around. The reason for this emphasis is that the great majority of laboratory tests are probabilistic rather than pathognomonic – which means that clinical judgment enters into their interpretation. <br /><br />Clinical science operates through a process of convergent validation. That is how disease constructs take form, through iterative attention to signs, symptoms, course of illness, response to treatments, family history, and laboratory data. This is an area where DSM-III and DSM-IV failed us by limiting their focus to signs and symptoms. Had the framers of DSM-III understood the original Washington University position, they would have incorporated course of illness, response to treatments, family history, and laboratory data into the manual. Instead, Spitzer rejected these potential validators, saying they might introduce circular logic, and that misstep has been carried forward. However, a positive family carries great diagnostic weight in Huntington’s disease; likewise neurologists routinely use response to l-DOPA as a diagnostic test of Parkinson’s disease (to distinguish it from look-alike disorders).<br /> <br />This process of convergent validation has given us an A-list of psychiatric diagnoses that are candidate brain diseases. Here is the list: psychosis, mania, melancholia, vascular depression, crippling anxiety, panic disorder, dementia, autism, obsessive-compulsive disorder, delirium, catatonia, and more. <br /> <br />The fact that we have not nailed the pathophysiology of these conditions does not invalidate the diagnoses, however. We knew about Huntington’s disease and correctly diagnosed it for 110 years before its genetic basis was discovered. If you want the objective validity that Insel and Kupfer naively aspire to, then by all means tell the magistrate at your next commitment hearing that you were serious when you commandeered an airliner, prevented the scheduled passengers from boarding it, declared yourself the owner of the airline, announced that you were going to fly your entire extended family to London to meet with Margaret Thatcher, and that the psychiatrist who said you suffer from mania must be wrong because he hasn’t shown the court a laboratory diagnostic test for mania.<br /><br />There is no problem with the clinical validity of most psychiatric diagnoses. <br />Bernard Carrollhttps://www.blogger.com/profile/16203083806436919715noreply@blogger.com