Featured Research

from universities, journals, and other organizations

PTSD linked to smaller brain area regulating fear response

Date:
November 5, 2012
Source:
Duke University Medical Center
Summary:
Recent combat veterans who are diagnosed with post traumatic stress disorder have significantly smaller volume in an area of the brain critical for regulating fear and anxiety responses, according to new research.

CAT scans. Recent combat veterans who are diagnosed with post traumatic stress disorder have significantly smaller volume in an area of the brain critical for regulating fear and anxiety responses.
Credit: svedoliver / Fotolia

Recent combat veterans who are diagnosed with post traumatic stress disorder have significantly smaller volume in an area of the brain critical for regulating fear and anxiety responses, according to research led by scientists at Duke University and the Durham VA Medical Center.

The finding, published Nov. 5, 2012, in the journal Archives of General Psychiatry, for the first time provides clear evidence that smaller amygdala volume is associated with PTSD, regardless of the severity of trauma. But it's not clear whether the physiological difference was caused by a traumatic event, or whether PTSD develops more readily in people who naturally have smaller amygdalas.

"Researchers found 20 years ago that there were changes in volume of the hippocampus associated with PTSD, but the amygdala is more relevant to the disorder," said Rajendra A. Morey, M.D., M.S., assistant professor at Duke and lead author of the study. Morey said studies in animals have established the amygdala's role in regulating fear, anxiety and stress responses, but its effect on human behavior is less well known.

"It's associated with how fear is processed, especially abnormal fear processing." Morey said. "So it makes sense to look at the structure of the amygdala."

The researchers enrolled 200 combat veterans who served in Iraq and Afghanistan after Sept. 11, 2001; half had PTSD and the other half had been exposed to trauma, but had not developed PTSD. Amygdala and hippocampus volumes were computed from MRI scans of all the participants.

The researchers found significant evidence that PTSD among study participants was associated with smaller volume in both the left and right amygdala, and confirmed previous studies linking the disorder to a smaller left hippocampus. The differences in brain volumes between the two groups were not due to the extent of depression, substance abuse, trauma load or PTSD severity -- factors the researchers took into account in their statistical model.

The finding provides new insight into a condition that strikes nearly 14 percent of combat veterans serving in Iraq and Afghanistan, according to the Department of Veterans Affairs. PTSD is also estimated to afflict 6.8 percent of adults in the general population who have suffered abuse, crimes and other traumas over their lifetimes.

"The next step is to try to figure out whether a smaller amygdala is the consequence of a trauma, or a vulnerability that makes people get PTSD," Morey said.

He said the study demonstrated that amygdala volume does not appear to be affected by the severity, frequency or duration of trauma, indicating that such exposures do not cause the amygdala to shrink. As a result, it appears more likely that people with measurably smaller amygdala to begin with are susceptible to PTSD, but more studies are needed to make that determination.

Morey said he and colleagues are exploring that question, and are intrigued by evidence from their study that suggests people may have a propensity for developing PTSD based on inherently smaller amygdala volume.

"This is one piece in a bigger puzzle to understanding why some people develop PTSD and others do not," Morey said. "We are getting closer to that answer."

In addition to Morey, study authors include: Kevin S. LaBar; Shannon K. Beall; Vanessa M. Brown; Courtney C. Haswell; Jessica D. Nasser; H. Ryan Wagner. All are associated with Duke and the VA's Mental Illness Research Education and Clinical Center at the Durham VA Medical Center. Gregory McCarthy and Andrea L. Gold are from Yale University.

Funding for the study was from the U.S. Department of Veterans Affairs and the National Institutes of Health.


Story Source:

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


Journal Reference:

  1. Rajendra A. Morey et al. Amygdala Volume Changes in Posttraumatic Stress Disorder in a Large Case-Controlled Veterans Group. Arch Gen Psychiatry, 2012;69(11):1169-1178 DOI: 10.1001/archgenpsychiatry.2012.50

Cite This Page:

Duke University Medical Center. "PTSD linked to smaller brain area regulating fear response." ScienceDaily. ScienceDaily, 5 November 2012. <www.sciencedaily.com/releases/2012/11/121105161355.htm>.
Duke University Medical Center. (2012, November 5). PTSD linked to smaller brain area regulating fear response. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2012/11/121105161355.htm
Duke University Medical Center. "PTSD linked to smaller brain area regulating fear response." ScienceDaily. www.sciencedaily.com/releases/2012/11/121105161355.htm (accessed July 23, 2014).

Share This




More Mind & Brain News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Do Obese Women Have 'Food Learning Impairment'?

Do Obese Women Have 'Food Learning Impairment'?

Newsy (July 18, 2014) Yale researchers tested 135 men and women, and it was only obese women who were deemed to have "impaired associative learning." Video provided by Newsy
Powered by NewsLook.com
Does Mixing Alcohol and Energy Drinks Boost Urge To Drink?

Does Mixing Alcohol and Energy Drinks Boost Urge To Drink?

Newsy (July 18, 2014) A new study suggests that mixing alcohol with energy drinks makes you want to keep the party going. Video provided by Newsy
Powered by NewsLook.com
Pot Cooking Class Teaches Responsible Eating

Pot Cooking Class Teaches Responsible Eating

AP (July 18, 2014) Following the nationwide trend of eased restrictions on marijuana use, pot edibles are growing in popularity. One Boston-area cooking class is teaching people how to eat pot responsibly. (July 18) Video provided by AP
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