PTSD and The Effect on DNA Part 2
by Ed Mattson
Here we are at Part 2 in the discussion of PTSD’s ability to have an adverse effect on DNA. In Part 1 we discussed research that while not effecting the structure of DNA, PTSD has been shown to effect the function of genes. Here in Part 2 we will look at a possible way to address these genetic markers of Post Traumatic Stress Disorder, which could well provide long term solutions. To those suffering PTSD, such outside-the-box thinking would be most welcome.
One of the most comprehensive studies of the relationship between PTSD and the function of specific genes was done by Emory University and published by Elsevier Journal of Neuropharmacology in 2011. This 10 page report would warrant further reading by those interested in the complete in-depth study done by Emory on the three primary neuronal systems they have been investigating, the hypothalamic-pituitary-adrenal (HPA) axis, the locus coeruleus-noradrenergic (LC) system, and the neurocircuitry interconnecting the limbic system and frontal cortex.
While the literature on the genetics of PTSD is relatively in the early stages, it is rapidly evolving with an increasing number of studies demonstrating important interactions in Gene/Environment situations associated with risk for PTSD. It can be anticipated that in the coming years, the field will see advances in identifying novel genes associated with PTSD leading to unique new treatment protocols. So as not to be confusing, the term “environment” is used to cover the environment in which the individual is exposed taking into consideration social factors, personality factors, family history (possibly including hereditary association), and dynamics, not the environment so over-used by many pertaining to Mother Nature and “pollution crisis”.
From an interesting New York Times article on PTSD and the influence on genetics:
Children’s personalities may indicate higher or lower risk for future anxiety disorders. For example, research suggests that extremely shy children and those likely to be the target of bullies are at higher risk for developing anxiety disorders later in life. Children who cannot tolerate uncertainty tend to be worriers, a major predictor of generalized anxiety. In fact, such traits may be biologically based and due to a hypersensitive amygdale (which we discussed in Part 1) — the “fear center” in the brain.
Anxiety disorders tend to run in families. Genetic factors may play a role in some cases, but family dynamics and psychological influences are also often at work. Several studies show a strong correlation between a parent’s fears and those of the offspring. Although an inherited trait may be present, some researchers believe that many children can “learn” fears and phobias, just by observing a parent or loved one’s phobic or fearful reaction to an event.
Several studies have reported a significant increase in anxiety levels in children and college students in the past two decades compared to children in the 1950s. In several studies, anxiety was associated with a lack of social connections and a sense of a more threatening environment. It also appears that more socially alienated populations have higher levels of anxiety.
Traumatic events may trigger anxiety disorders, especially in individuals who are susceptible to them because of psychological, genetic, or biochemical factors. The clearest example is post-traumatic stress disorder. Specific traumatic events in childhood, particularly those that threaten family integrity, such as spousal or child abuse, can also lead to other anxiety and emotional disorders. Some types of specific phobias, for instance of spiders or snakes, may be triggered and perpetuated after a single traumatic exposure.
Traumatic events are the main risk factor for PTSD, but some people can go through such events and not experience PTSD. Studies estimate that up to 30% or more of trauma survivors develop some degree of PTSD, with children and young people being most vulnerable, and with women having twice the risk as men. Studies are seeking to find more definitive factors that increase the vulnerability to events for putting people at risk and are looking at factors, some of which have long been thought to affect our genes in some form or another:
- Family history
- Drug and/or alcohol abuse, nicotine addiction
- Physical, sexual, or emotional abuse
- In children…early departure from the “home environment”
- Poverty and/or dependence on government social services support
- Pre-existing disorders or exposure to other traumatic events
- Divorce and poor family support
- Sleep disorders such as sleep apnea and insomnia
The hippocampus, a structure inside the brain, shrinks after psychological trauma, which hints that a pharmaceuticals can address post-traumatic stress disorder. Shrinkage of the hippocampus is a common condition among post-traumatic stress disorder patients. What hasn’t been clear until recently is whether a smaller hippocampus leaves a person predisposed to PTSD or whether shrinkage results from the stress experienced. If this vital part of the brain is too small or has experienced shrinkage it would help explain flashbacks.
“The hippocampus plays a big role in storing memories, but it’s also important in recalling them,” says Ulrike Schmidt, a senior psychiatrist and research group leader at the Max Planck Institute of Psychiatry in Munich, “and this recall is obviously disrupted in PTSD patients.”
The hippocampus is one seat of the problem, but scientists have also noticed effects on the epigenome (the study of change in gene function rather than changes in DNA). It’s a flexible system that responds to the environment. Two people hardwired for the same trait might not show the trait in the same way because they have epigenetic differences that mute or emphasize the genes. The epigenome is important in controlling stress hormones, including cortisol (cortisol helps the body use sugar-glucose and fat for energy metabolism), and it helps the body manage stress, which is released by the adrenal gland when the brain and body react to danger.
Cortisol, moreover, acts on the hippocampus, so the large amounts of cortisol squeezed into the blood during an intense or long-lasting trauma can also explain hippocampal shrinkage. Long-term exposure to stress hormones can cause atrophy of the hippocampus, leading to memory impairment.
Cortisol shrinks the thymus gland – one of the key immune regulators in the body – and inhibits white blood cell activity and production. It can actually signal immune-system cells to shut down and die. Prolonged exposure can cause the same immune system cells to attack the body’s own tissue leading to autoimmune system diseases. Additionally, the immune system may overreact causing allergies, asthma and various immune system disorders like rheumatoid arthritis, lupus, irritable bowel syndrome, Crohn’s disease and fibromyalgia. Eventually, long-term exposure may lead to immune system suppression and far more serious diseases caused by the inactivation of our immune system protection.
Furthermore, stress inhibits the production and activity of natural killer cells, known as NK cells, as much as 50%. NK cells are responsible for identifying and destroying cancer, virus cells, and non-self cells (invaders). Even more scary, chronic stress can accelerate the growth of cancer cells in the body as well as block the body’s ability to fight cancer. It promotes the synthesis of new blood cells in tumors and accelerates the growth of some tumors.
Let’s take a closer look at Gamma-aminobutyric acid (GABA) and its role in PTSD. GABA is
the brain’s principal inhibitory neurotransmitter (also called g-amino-butyric acid), along with serotonin and norepinephrine, is one of several neurotransmitters that appear to be involved in the pathogenesis of anxiety and mood disorders. It exerts a prominent effect on central stress responses in times of high stress and has been associated with acute post traumatic stress disorder (PTSD). According to PubMED, it is possible to measure the plasma GABA levels to see the effect on PTSD. A plasma GABA level above 0.20 mmol/ml may protect against chronic PTSD and may represent a marker of recovery from trauma. This will certainly help researchers in developing treatment protocols.
GABA-enhancing agents have shown early evidence of efficacy in several neuropsychiatric disorders. Several drugs have GABAergic (transmitting or secreting γ-aminobutyric acid) mechanisms, and produce anxiolytic (a drug that inhibits anxiety) effects in preclinical models of anxiety, and varying degrees of clinically relevant anxiolytic effects. Among these drugs tiagabine, topiramate, valproate, and carbamazepine, have shown evidence of efficacy in post-traumatic stress disorder (PTSD). One of the cardinal features of PTSD is nocturnal awakening associated with vivid and very frightening nightmares. Tiagabine normalizes sleep architecture or sleep disturbance in many patients with PTSD and, in addition, reduced arousal, agitation, anxiety, and the frequency of flashbacks.
GABA has been the subject of numerous studies on panic disorders as well as other psychiatric disorders and substance abuse conditions. Scientists believe that GABA, a brain chemical, works by limiting the nerve cell activity in areas of the brain associated with anxiety. GABA is an amino acid produced in the brain that functions as an inhibitory neurotransmitter.
It has been hypothesized that people with anxiety disorders have increased cell activity in these areas. Another theory, is that people with anxiety and/or panic disorders have abnormally low levels of GABA. For relief of chronic anxiety, some PTSD specialists may recommend 750-1000 mg of GABA supplement three times per day. This is a natural approach and has some merit.
With a better understanding of gene interaction involve GABA and other genes, plus the use of already developed drugs like tiagabine, topiramate, valproate, and carbamazepine, I am convinced we are on the verge of unlocking the key to post traumatic stress disorder.
As I have written about in previous articles, genetics plays a role in our overall health, from wound healing to viral/bacterial/fungal infection, and from responding to abnormal cell development like in cancer, to other life threatening diseases. It is no wonder then that U.S. researchers will one day reach a consensus that’s already been proven and is being used in many other countries, regarding the use of biological response modifiers to solve the problems many Veterans and others are facing with PTSD.
As discussed in this article, GABA, the brain’s principal inhibitory neurotransmitter, along with serotonin and norepinephrine, is one of several neurotransmitters that appear to be involved in the pathogenesis of anxiety and exerts a prominent effect on central stress responses in times of high stress associated with acute PTSD. We can begin to use this understanding even without further study to make life better for those suffering PTSD.
The same is true with cortisol which is released by the adrenal gland when the brain and body react to danger. Over-secretion of cortisol can cause extreme damage to one’s immune system so that it becomes muted and can no longer respond to the many cellular abnormalities, viral, fungal, bacterial and many other non-self conditions that create life-threatening disease.
My website, Docmattson.com, gives an in depth review of biological response modifiers, particularly ALL NATURAL, beta glucan and resveratrol, which has a proven track record of success in helping the immune system handle stress as describled in D.J.Carrow’s peer-reviewed study on Beta-1,3-glucan…
Stress – Physical or Emotional: Carrow, D.J.; “Beta-1,3-glucan as a Primary Immune Activator,” Townsend Letter; June 1996. Quote: “The following list includes benefits from the use of Beta 1,3-glucan supplementation: Professional and amateur athletes as well as people who work outdoors intensively and people under physical or emotional stress”.
Please feel free to share this important information with those you know who are suffering from post traumatic stress disorder. Many of those we know are fighting the flashbacks, the demons, and trying to survive in a world that just doesn’t make sense any more. With a record number of suicide attempts among Veterans, and a number of fatal suicides achieved nearing the rate of one every hour we must do everything in our power to help our brothers and sisters so easily neglected by the government they so valiantly served.
Short URL: http://www.veteranstoday.com/?p=267162
Posted by Ed Mattson on Sep 2 2013, With 0 Reads, Filed under Coping, Editor, Health, PTSD. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.