Featured Research

from universities, journals, and other organizations

A brain signal for psychosis risk

Date:
March 13, 2014
Source:
Elsevier
Summary:
Only one third of individuals identified as being at clinical high risk for psychosis actually convert to a psychotic disorder within a three-year follow-up period. This risk assessment is based on the presence of sub-threshold psychotic-like symptoms. Thus, clinical symptom criteria alone do not predict future psychosis risk with sufficient accuracy to justify aggressive early intervention, especially with medications such as antipsychotics that produce significant side effects.

Only one third of individuals identified as being at clinical high risk for psychosis actually convert to a psychotic disorder within a 3 year follow-up period. This risk assessment is based on the presence of sub-threshold psychotic-like symptoms.

Thus, clinical symptom criteria alone do not predict future psychosis risk with sufficient accuracy to justify aggressive early intervention, especially with medications such as antipsychotics that produce significant side effects.

Accordingly, there is a strong imperative to develop biomarkers of psychosis risk that can improve the ability to predict which individuals are most likely to transition to a psychotic disorder.

A study published in the current issue of Biological Psychiatry provides evidence that mismatch negativity (MMN), an event-related brain potential component derived from scalp electroencephalography (EEG) recordings, may be such a biomarker.

Mismatch negativity is an EEG signal that is elicited automatically from auditory cortex and frontal lobe regions of the brain in response to sounds that deviate from preceding sounds in pitch, duration, or other auditory features, even when one is not paying attention to the sounds. This electrophysiological measure of auditory deviance detection is thought to reflect short term plasticity in the brain, since it depends on the formation of a short term memory of recently heard sounds in order to detect a deviant sound.

Mismatch negativity is known to be reduced in patients with full-blown schizophrenia. So, to conduct this study, researchers assessed MMN in patients with schizophrenia, patients at clinical high risk for psychosis, and healthy control subjects. Compared to the healthy subjects, MMN was reduced in the patients with schizophrenia, as expected, but was also reduced in the high-risk patients. Analyses showed that MMN did not differ between the two patient groups.

"Our study results show that mismatch negativity deficits precede the onset of psychosis in clinical high risk individuals, and further shows that the larger the deficit, the more imminent the risk for conversion to a psychotic disorder," said Dr. Daniel Mathalon, Professor of Psychiatry at the University of California, San Francisco and senior author on the paper.

In addition, they also followed the clinical high-risk group for over twelve months and compared those who converted to a psychotic disorder with those who did not. MMN was reduced in those individuals who ultimately developed a psychotic disorder, compared to those who remained only in the clinical high risk category.

Mathalon added, "Importantly, our study results converge with those reported by several other studies from researchers in Europe and Asia. This remarkable convergence of findings points to the mismatch negativity as a promising EEG-based biomarker of psychosis risk that, with further development, could enhance our ability to identify which individuals are at greatest risk for psychosis and in greatest need of early treatment, particularly if the treatment is associated with potential adverse effects (such as antipsychotic medication)."

Indeed, there is substantial interest in developing diagnostic and prognostic tests for psychiatric disorders. "We do not currently use tests to help us make diagnoses or to inform patients about the likely long-term course of their illness," commented Dr. John Krystal, Editor of Biological Psychiatry. "However, this study suggests that one day it may be possible to develop this type of test."


Story Source:

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


Journal Reference:

  1. Veronica B. Perez, Scott W. Woods, Brian J. Roach, Judith M. Ford, Thomas H. McGlashan, Vinod H. Srihari, Daniel H. Mathalon. Automatic Auditory Processing Deficits in Schizophrenia and Clinical High-Risk Patients: Forecasting Psychosis Risk with Mismatch Negativity. Biological Psychiatry, 2014; 75 (6): 459 DOI: 10.1016/j.biopsych.2013.07.038

Cite This Page:

Elsevier. "A brain signal for psychosis risk." ScienceDaily. ScienceDaily, 13 March 2014. <www.sciencedaily.com/releases/2014/03/140313092414.htm>.
Elsevier. (2014, March 13). A brain signal for psychosis risk. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2014/03/140313092414.htm
Elsevier. "A brain signal for psychosis risk." ScienceDaily. www.sciencedaily.com/releases/2014/03/140313092414.htm (accessed July 25, 2014).

Share This




More Mind & Brain News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 Video provided by AFP
Powered by NewsLook.com
Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. 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