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Article Date: 01 Oct 2009 – 5:00 PDT


The brain is a complex system made of billions of neurons and thousands of connections that relate to every human feeling, including one of the strongest emotions, fear. Most neurological fear studies have been rooted in fear-conditioning experiments. Now, University of Missouri researchers have started using computational models of the brain, making it easier to study the brain’s connections. Guoshi Li, an electrical and computer engineering doctoral student, has discovered new evidence on how the brain reacts to fear, including important findings that could help victims of post-traumatic stress disorder (PTSD).


“Computational models make it much easier to study the brain because they can effectively integrate different types of information related to a problem into a computational framework and analyze possible neural mechanisms from a systems perspective. We simulate activity and test a variety of “what if” scenarios without having to use human subjects in a rapid and inexpensive way,” Li said.


From previous experiments, scientists have found that fear can subside when overcome with fear extinction memory, but it is not permanently lost. Fear extinction is a process in which a conditioned response to a stimulant that produces fear gradually diminishes over time as subjects, such as rats in auditory fear experiments, learn to disassociate a response from a stimulus. One theory has concluded that fear extinction memory deletes fear memory, and another concluded that fear memory is not lost, but is inhibited by extinction memory as fear can recover with the passage of time after extinction.


Read in Full:  http://www.medicalnewstoday.com/articles/165875.php


Abstract: PTSD is associated with an excess of inflammatory immune activities


Gill JM, Saligan L, Woods S, Page G.


National Institutes of Health, National Institutes of Nursing Research, Bethesda, Maryland; University of Akron, School of Nursing, Akron, Ohio; Johns Hopkins University, School of Nursing, Bethesda, Maryland, USA.


PURPOSE. Post-traumatic stress disorder (PTSD) is associated with inflammatory-related medical conditions. This review examines studies of immune function in individuals with PTSD to determine if excessive inflammation is associated with PTSD.


CONCLUSIONS. Current studies suggest an excess of inflammatory actions of the immune system in individuals with chronic PTSD. High levels of inflammatory cytokines have also been linked to PTSD vulnerability in traumatized individuals. There is also evidence that excessive inflammation is in part due to insufficient regulation by cortisol.


PRACTICE IMPLICATIONS. An excess of inflammatory immune activity may contribute to health declines in individuals with PTSD, and treating PTSD symptoms may reduce these risks.


Source… © 2009 Wiley Periodicals, Inc.


Iraq veterans developing PTSD at twice the expected rate


Barry List – INFORMS


The Veterans’ Administration should expect a high volume of Iraq veterans seeking treatment of post traumatic stress disorder, with researchers anticipating that the rate among armed forces will be as high as 35%, according to the Management Insights feature in the current issue of Management Science, the flagship journal of the Institute for Operations Research and the Management Sciences (INFORMS®).


The tempo of deployment cycles in the Iraq War is higher than for any war since World War II, Michael P. Atkinson of the Naval Postgraduate School and Adam Guetz and Lawrence M. Wein of Stanford University write, and military survey data suggest that posttraumatic stress disorder (PTSD) is common among service members.


To assure ample mental health resources to care for returning troops, the authors argue that it is important for the Department of Veterans Affairs (VA) to forecast the timing and number of new PTSD cases over the coming years, which is complicated by the fact that many cases have delayed onset.


The authors combine a dynamic mathematical operations research model with deployment data and PTSD data from the Iraq War, and estimate that the PTSD rate among Iraq War veterans will be approximately 35%, which is roughly double the rate from the raw survey data. This doubling is due to the time lag between the PTSD-generating event and the onset of symptoms and to the fact that many surveyed troops will do subsequent deployments.


Consequently, the authors write, the VA system, which is already experiencing significant delays for PTSD treatment provision, urgently needs to ramp up its mental health resource capacity.


Atkinson MP, Guetz A, Wein LM. A Dynamic Model for Posttraumatic Stress Disorder Among U.S. Troops in Operation Iraqi Freedom. Management Serv. 2009 Sept;55(9):1454-1468   [Abstract (PDF)]


Abstract: Low cerebrospinal fluid neuropeptide y concentrations in PTSD


Sah R, Ekhator NN, Strawn JR, Sallee FR, Baker DG, Horn PS, Geracioti TD Jr.


Department of Psychiatry, University of Cincinnati, Cincinnati, Ohio; Research Service, Veterans Affairs Medical Center, Cincinnati, Ohio; Department of Mathematical Sciences, University of Cincinnati, Cincinnati, Ohio; Department of Psychiatry, University of California, San Diego, California; Veterans Affairs San Diego Healthcare System, San Diego, California


Background: Neuropeptide Y (NPY), a peptide neurotransmitter that regulates stress and anxiety, has been proposed to be a stress resilience factor in humans. Posttraumatic stress disorder (PTSD) is a stress-related anxiety disorder. We hypothesized that central nervous system NPY is dysregulated in PTSD and sought to redress the absence of central NPY data in the disorder.


Methods: We determined morning NPY concentrations in cerebrospinal fluid (CSF) from 10 male subjects with chronic combat-related PTSD and from 13 healthy men. Neuropeptide Y-like immunoreactivity was measured by enzyme immunoassay (EIA).


Results: As compared with the normal comparison subjects, PTSD patients had significantly lower concentrations of CSF neuropeptide Y (mean CSF NPY was 360.0 ± 17.7 pg/mL in control subjects but only 233.6 ± 28.7 pg/mL in PTSD patients [p = .0008]). Adjustments for age and body mass index (BMI) still revealed a highly significant reduction in CSF NPY in the PTSD group (p = .003).


Conclusions: Men with combat-related PTSD have low CSF concentrations of the putative resiliency hormone NPY, possibly related to the disorder or to extreme stress exposure per se.


Source…



© 2009 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.


Cognitive changes linked to PTSD in war veterans


Soldiers who have intense or traumatic combat experiences exhibit evidence of cognitive changes


JAMA


In a study of whether neuropsychological changes occur following deployment to war zones, post-traumatic stress disorder appeared to be associated with attention deficits in soldiers one year after returning from Iraq, according to a report in the September issue of Archives of General Psychiatry, one of the JAMA/Archives journals. In addition, intense combat experiences were associated with faster reaction times regardless of how recently a soldier was deployed.


Previous research has suggested that as soldiers face prolonged stressful and life-threatening situations, changes in their brains direct their cognitive (thinking, learning and memory) resources toward survival, according to background information in the article. For instance, they may respond to dangerous events more quickly while losing the ability to pay attention, learn and remember events not related to combat. “However, it remains unknown whether deployment-related neuropsychological changes persist over time, are associated with stress-related factors (e.g., combat intensity, posttraumatic stress disorder [PTSD] symptoms and depressive reactions) or are better accounted for by demographic and contextual variables,” the authors write.


Brian P. Marx, PhD, of Veterans Affairs Boston Healthcare System and Boston University School of Medicine, and colleagues studied 268 male and female regular active-duty soldiers who served between 2003 and 2006. All the soldiers were given neuropsychological tests measuring response time, attention and memory before and after deployment. A group of 164 was assessed both immediately and one year following their return, whereas a second group of 104 returned more recently and were assessed before deployment and then a median (midpoint) of 122 days after returning. The assessments also documented demographic and military information, risk factors for neuropsychological disorders and combat intensity and emotional distress.


Greater PTSD symptoms were associated with poorer attention in soldiers tested at one-year follow-up but not in recently returned soldiers,” the authors write. “Greater combat intensity was associated with enhanced reaction time, irrespective of time since return.” Neither depression nor risk-related variables such as alcohol use and head injury were associated with changes in neuropsychological functioning.


Recent findings reveal notably high rates of poor mental health outcomes among U.S. service members upon return from Iraq deployment,” the authors write. “Our findings additionally highlight the neuropsychological consequences of chronic PTSD symptoms. Although neuropsychological changes were not profound and, for reaction time, can be construed as desirable in the short term, their significance lies in the demonstration that psychiatric symptoms often reflect more extensive biological changes, including those affecting brain functioning.


A growing literature demonstrates the significant impact of prolonged and repetitive stress on health factors (e.g., immune functioning, cardiovascular disease and other systemic medical illnesses) that can be traced to the biological stress response. Thus, subtle cognitive changes (positive or negative) associated with combat exposure or PTSD may represent a warning sign relevant to long-term health,” they add.


This work was supported by U.S. Army Medical Research and Materiel Command and Veterans Affairs Clinical Sciences Research and Development awards. This work was also supported in part by resources provided by the South Central Mental Illness Research, Education and Clinical Center and U.S. Army Research Institute for Environmental Medicine.


Marx BP, Brailey K, Proctor SP, et al. Association of Time Since Deployment, Combat Intensity, and Posttraumatic Stress Symptoms With Neuropsychological Outcomes Following Iraq War Deployment. Arch Gen Psychiatry. 2009;66(9):996-1004 [Abstract]


Doctor eyes link between PTSD, alcoholism


McClatchy-Tribune Information Services — A Yale University physician is attending the Military Health Research Forum in Kansas City, Mo., this week to present her work helping veterans who suffer from both post-traumatic stress disorder and alcoholism.


More…



Copyright (c) 2009, New Haven Register, Conn.


‘Brain profiling’ may predict post trauma suicidality


Breakthrough predictive tool used to detect at-risk combat soldiers


George Hunka


According to a recent Washington Post report, approximately 20% of U.S. soldiers returning from Iraq and Afghanistan are psychologically damaged. Among them are a substantial number with post-traumatic stress disorder (PTSD), and the high rate of suicide among PTSD sufferers has become unacceptable to Army commanders and the soldiers’ families.


Thanks to new research from Tel Aviv University published in the August issue of the Proceedings of the National Academy of Sciences, however, doctors may now be able to forecast a soldier’s chances of falling prey to PTSD, with the chance of intervening to prevent military-related suicides.


Prof Talma Hendler of TAU’s Department of Psychology and Psychiatry and the founding director of the Tel Aviv Functional Brain Center and colleagues have developed a new predictive tool for detecting at-risk soldiers. The tool will permit clinicians to diagnose and treat these soldiers immediately before the stressors of combat lead to chronic psychological problems. Studying a group of 50 Israeli soldiers — trained medics who experienced extreme stress in live combat zones — Prof Hendler and her graduate student Roee Admon in collaboration with Col. Dr Gad Lubin from the Israel Defense Forces were able to predict which soldiers would develop significant increases in stress symptoms such as mood decline, intrusive thoughts, and sleep disturbance.


Prof Hendler’s research shows functional magnetic resonance imaging (fMRI) can be used to forecast which soldiers might be vulnerable to stress psychopathology in the future. The non-invasive imaging method records the brain activity of military personnel before they enter active duty. Using this baseline as a reference, the researchers can predict which soldier is more prone to exhibit after exposure combat-related stress symptoms — symptoms that can trigger PTSD or major depression.


The TAU researchers measured the levels of “stress symptoms” twice: first when the soldiers were drafted, then again a year-and-a-half later, during their active duty in combat units. The soldiers were also asked a series of questions evaluating their experience in the army. With this data, researchers developed predictive brain measurements for whether or not a soldier would develop stress.


Having such an early biological marker, says Prof Hendler, means that diagnosis and treatment can begin immediately following exposure to situational trauma. It is the first fMRI-based study to measure brain activation under stress over a long period of time with respect to prior to stress.


Looking at the part of the brain called the amygdala, we were able to predict how many stress symptoms of PTSD an individual soldier would develop,” says Prof Hendler. She notes that other brain activity was modified by the stress giving indications of the appropriate intensity and approach of treatment after the stress and trauma set in. Prof Hendler is currently planning a larger study in this direction.


While Prof Hendler doesn’t believe that the fMRI should be used prejudicially to weed soldiers from certain units, she says that it does give specialists a new set of clues as to how to treat soldiers early and effectively, decreasing the rates of military suicide. This field of science is applied in a growing specialty known as “personalized medicine.”


This tool can help provide tailored therapy to the afflicted and at a very early stage could identify the extreme cases that might otherwise go unnoticed,” says Prof Hendler.


Admon R, Lubin G, Stern O, et al. Human vulnerability to stress depends on amygdala’s predisposition and hippocampal plasticity Proc Natl Acad Sci U S A. 2009 Aug 18;106(33):14120-5 [Abstract]




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