Psych Central News
Even Without Stress, PTSD Effects Persist in Brain Regions
Prior imaging studies of people with PTSD have shown that these brain regions can over- or underreact in response to stressful tasks, such as recalling a traumatic event or reacting to a photo of a threatening face.
Researchers now believe chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety.
In the new study, researchers at New York University School of Medicine explored for the first time what happens in the brains of combat veterans with PTSD in the absence of external triggers.
Investigators say the findings, published in Neuroscience Letters, show that the effects of trauma persist in certain brain regions even when combat veterans are not engaged in cognitive or emotional tasks, and face no immediate external threats.
Experts believe this knowledge is a critical step toward better diagnostics and treatments for PTSD as it shows which areas of the brain provoke traumatic symptoms.
PTSD can plague victims with disturbing memories, flashbacks, nightmares and emotional instability. Among the 1.7 million men and women who have served in the wars in Iraq and Afghanistan, an estimated 20 percent have PTSD. Research shows that suicide risk is higher in veterans with PTSD.
Tragically, more soldiers committed suicide in 2012 than the number of soldiers who were killed in combat in Afghanistan that year.
“It is critical to have an objective test to confirm PTSD diagnosis as self-reports can be unreliable,” said co-author Charles Marmar, M.D.
The study, led by Xiaodan Yan, a research fellow at NYU School of Medicine, examined “spontaneous” or “resting” brain activity in 104 veterans of combat from the Iraq and Afghanistan wars using functional MRI, which measures blood-oxygen levels in the brain.
The researchers found that spontaneous brain activity in the amygdala, a key structure in the brain’s “fear circuitry” that processes fearful and anxious emotions, was significantly higher in the 52 combat veterans with PTSD than in the 52 combat veterans without PTSD.
The PTSD group also showed elevated brain activity in the anterior insula, a brain region that regulates sensitivity to pain and negative emotions.
Moreover, the PTSD group had lower activity in the precuneus, a structure tucked between the brain’s two hemispheres that helps integrate information from the past and future, especially when the mind is wandering or disengaged from active thought.
Decreased activity in the precuneus correlates with more severe “re-experiencing” symptoms—that is, when victims re-experience trauma over and over again through flashbacks, nightmares and frightening thoughts.
Source: NYU Langone Medical Center / New York University School of Medicine
Abstract of a person’s brain photo by shutterstock.
Work Stress, Unhealthy Lifestyle Impact Coronary Arteries
As reported in the CMAJ (Canadian Medical Association Journal), researchers discovered people with job stress and an unhealthy lifestyle are at higher risk of coronary artery disease than people who have job stress but lead healthy lifestyles.
Researchers studied the effect of a healthy lifestyle on reducing the effects of stress on coronary artery disease by reviewing seven cohort studies from a European initiative that included more than 100,000 people.
Subjects were disease-free during the 15-year study period (1985-2000), ranged in age from 17 to 70 (mean 44.3) years, and resided in the United Kingdom, France, Belgium, Sweden and Finland. More than half (52 percent) were women.
Of the total participants, nearly 16,000 individuals (16 percent) reported job stress, which was determined from specific job-related questions in the studies.
The investigators defined three lifestyle categories based on smoking, alcohol consumption, physical activity/inactivity and obesity (body mass index).
A “healthy lifestyle” had no lifestyle risk factors, “moderately unhealthy lifestyle” had one risk factor and “unhealthy lifestyle” included 2 to 4 lifestyle risk factors.
A total of 1,086 participants had incident events of coronary artery disease events during the followup period.
The 10-year incidence of coronary artery disease was 18.4 per 1000 people for people with job strain and 14.7 for those without job strain.
People with an unhealthy lifestyle had a significantly higher 10-year incidence rate (30.6 per 1000) compared to those with a healthy lifestyle (12.0 per 1000). The incidence rate was 31.2 per 1000 for participants with job strain and an unhealthy lifestyle but only 14.7 for those with job strain and a healthy lifestyle.
“The risk of coronary artery disease was highest among participants who reported job strain and an unhealthy lifestyle; those with job strain and a healthy lifestyle had about half the rate of this disease,” said researcher Mika Kivimäki, Ph.D.
“These observational data suggest that a healthy lifestyle could substantially reduce the risk of coronary artery disease risk among people with job strain.”
Evidence from randomized controlled trials has shown that lifestyle changes such as weight loss and stopping smoking can reduce the risk of disease.
“In addition to stress counseling, clinicians might consider paying closer attention to lifestyle risk factors in patients who report job strain,” the authors conclude.
Source: Canadian Medical Association Journal
Stethoscope shaped as a person photo by shutterstock.
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