Nurture trumps nature in determining severity of PTSD symptoms — ScienceDaily

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Researchers at Yale and elsewhere previously identified a host of genetic risk factors that help explain why some veterans are especially susceptible to the debilitating symptoms of post-traumatic stress disorder (PTSD).

A new Yale-led study published Oct. 1 in the journal Biological Psychiatry has now identified a social factor that can mitigate these genetic risks: the ability to form loving and trusting relationships with others.

The study is one of the first to explore the role of nurture as well as nature in its investigation of the biological basis of PTSD.

“We exist in a context. We are more than our genes,” said Yale’s Robert H. Pietrzak, associate professor of psychiatry and public health, and senior author of the study.

Pietrzak is also director of the Translational Psychiatric Epidemiology Laboratory of the Clinical Neurosciences Division of the U.S. Department of Veterans Affairs National Center for PTSD.

Like many genetic studies on mental disorders such as depression, anxiety, and schizophrenia, PTSD studies have revealed numerous genetic risk factors that contribute to the severity of the disorder. For instance, a previous study of more than 165,000 U.S. military veterans led by Yale’s Joel Gelernter, the Foundations Fund Professor of Psychiatry and professor of genetics and of neuroscience, found variants in eight separate regions of the genome that help predict who is most likely to experience the repeated disturbing memories and flashbacks that are hallmark symptoms of PTSD.

In the new study, Pietrzak, Gelernter, and colleagues looked at psychological as well as genetic data collected from the National Health and Resilience in Veterans Study, which surveyed a national sample of U.S. military veterans, and is supported by the National Center for PTSD. The researchers specifically focused on a measure of attachment style — the ability or inability to form meaningful relations with others

Researchers have found connections in the brain to dissociative symptoms — ScienceDaily

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Being traumatized can cause what are known as dissociative symptoms — such as experiencing amnesia, an out-of-body experience, feeling emotionally numb — which may help people cope. Experiencing these symptoms intensely or for a long time, however, can negatively impact an individual’s ability to function.

A team led by investigators at McLean Hospital has now found that brain imaging analyses can uncover changes in functional connections between brain regions linked to a specific individual’s dissociative symptoms following trauma. The findings, which have been published in The American Journal of Psychiatry, may be useful for tailoring treatments for affected patients.

For the study, the researchers applied a novel machine-learning (artificial intelligence) technique to functional magnetic resonance imaging tests of 65 women with histories of childhood abuse and current post-traumatic stress disorder (PTSD). The technique, developed by one of the lead authors, Meiling Li, PhD, from Athinoula A. Martinos Center for Biomedical Imaging, showed that measurements related to connections between different regions of the brain correlated with dissociative symptoms in the women.

“This moves us one step closer to identifying a ‘fingerprint’ of dissociation in the brain that could be used as an objective diagnostic tool,” said one of the lead authors, Lauren A.M. Lebois, PhD, director of neuroimaging in the Dissociative Disorders and Trauma Research Program at McLean Hospital. “In the future, once brain-based measures reach high levels of sensitivity and specificity, we could use these assessments in individuals who are unable to effectively talk about their symptoms — for example, those who might intentionally or unintentionally minimize or exaggerate their symptoms — or in situations like court proceedings where objective corroborating evidence is requested.”

Lebois noted that the existence of dissociative symptoms and dissociative disorders is often doubted, and people are rarely asked about them. “This doubt in the lay