Featured Research

from universities, journals, and other organizations

Using Genetics To Improve Traditional Psychiatric Diagnoses

Date:
July 17, 2008
Source:
Elsevier
Summary:
Psychiatry has begun the laborious effort of preparing the DSM-V, the new iteration of its diagnostic manual. In so doing, it once again wrestles with the task set by Carl Linnaeus, to "cleave nature at its joints." However, these "joints," the boundaries between psychiatric disorders, such as that between bipolar disorder and schizophrenia, are far from clear. We now know that symptoms of bipolar disorder may be seen in patients with schizophrenia and the reverse is true, as well.

Psychiatry has begun the laborious effort of preparing the DSM-V, the new iteration of its diagnostic manual. In so doing, it once again wrestles with the task set by Carl Linnaeus, to "cleave nature at its joints." However, these "joints," the boundaries between psychiatric disorders, such as that between bipolar disorder and schizophrenia, are far from clear.

Prior versions of DSM followed the path outlined by Emil Kraeplin in separating these disorders into distinct categories. Yet, we now know that symptoms of bipolar disorder may be seen in patients with schizophrenia and the reverse is true, as well.

Further, our certainty about the boundary of these disorders is undermined by growing evidence that both schizophrenia and bipolar disorder emerge, in part, from the cumulative impact of a large number of risk genes, each of which conveys a relatively small component of the vulnerability to these disorders. And since many versions of these genes appear to contribute vulnerability to both disorders, the study of common gene variations has raised the possibility that there may be diagnostic, prognostic, and therapeutic meaning embedded in the high degree of variability in the clinical presentations of patients with each disorder.

In addition, many symptoms of schizophrenia and bipolar disorder are traits that are present in the healthy population but are more exaggerated in patient populations. To borrow from Einstein, who struggled to reconcile the wave and particle features of light, our psychiatric diagnoses behave like waves (i.e., spectra of clinical presentations) and particles (traditional categorical diagnoses). Although new genetic approaches may revise our current thinking, such as studies of microdeletions, microinsertions, and microtranslocations of the genome, the wave/particle approach to psychiatric diagnosis places a premium on understanding the "real" clustering of patients into subtypes as opposed to groups created to correspond to the current DSM-IV.

Latent class analysis is one statistical approach for estimating the clustering of subjects into groups. In their study of 270 Irish families, published in the July 15th issue of Biological Psychiatry, Fanous and colleagues conducted this type of analysis, with subjects clustered into the following groups: bipolar, schizoaffective, mania, schizomania, deficit syndrome, and core schizophrenia. When they divided the affected individuals in the study using this approach, they found four regions of the chromosome that were linked to the risk for these syndromes that were not implicated when subjects were categorized according to DSM-IV diagnoses. Dr. Fanous notes that this finding "suggests that schizophrenia as we currently define it may in fact represent more than one genetic subtype, or disease process."

According to John H. Krystal, M.D., Editor of Biological Psychiatry and affiliated with both Yale University School of Medicine and the VA Connecticut Healthcare System: "Their findings advance the hypothesis that the variability in the clinical presentation of patients diagnosed using DSM-IV categories is meaningful, providing information that may be useful as DSM-V is prepared. However, we do not yet know whether the categories generated by this latent class analysis will generalize to other populations." This paper highlights an important aspect of the complexity of establishing valid psychiatric diagnoses using a framework adopted from traditional categorical models.


Story Source:

The above story is based on materials provided by Elsevier. Note: Materials may be edited for content and length.


Journal Reference:

  1. Fanous et al. Novel Linkage to Chromosome 20p Using Latent Classes of Psychotic Illness in 270 Irish High-Density Families. Biological Psychiatry, 2008; 64 (2): 121 DOI: 10.1016/j.biopsych.2007.11.023

Cite This Page:

Elsevier. "Using Genetics To Improve Traditional Psychiatric Diagnoses." ScienceDaily. ScienceDaily, 17 July 2008. <www.sciencedaily.com/releases/2008/07/080717110258.htm>.
Elsevier. (2008, July 17). Using Genetics To Improve Traditional Psychiatric Diagnoses. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2008/07/080717110258.htm
Elsevier. "Using Genetics To Improve Traditional Psychiatric Diagnoses." ScienceDaily. www.sciencedaily.com/releases/2008/07/080717110258.htm (accessed April 16, 2014).

Share This



More Mind & Brain News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Are School Dress Codes Too Strict?

Are School Dress Codes Too Strict?

AP (Apr. 16, 2014) Pushing the limits on style and self-expression is a rite of passage for teens and even younger kids. How far should schools go with their dress codes? The courts have sided with schools in an era when school safety is paramount. (April 16) Video provided by AP
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Cognitive Function: Is It All Downhill From Age 24?

Cognitive Function: Is It All Downhill From Age 24?

Newsy (Apr. 15, 2014) A new study out of Canada says cognitive motor performance begins deteriorating around age 24. Video provided by Newsy
Powered by NewsLook.com
App Fights Jet Lag With The Power Of Math

App Fights Jet Lag With The Power Of Math

Newsy (Apr. 13, 2014) Researchers at the University of Michigan have designed an app to fight jet lag by adjusting your body's light intake. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins