A new study from researchers in the Netherlands, shows that persons who are affected with PTSD (Post-Traumatic Stress Disorder) can show changes in microRNA (miRNA) molecules that are linked to genetic regulation.
Professional therapist working with young soldier suffering from PTSD. Image Credit: Photographee.eu / Shutterstock
The team looked at the genetic markers among those deployed in the combat zone in Afghanistan to find these distinctive changes that could be potentially used in future to screen persons with PTSD. It also provides a deeper understanding of PTSD and other psychiatric disorders that are related to previous trauma. The results of this small pilot study will be presented at the European College of Neuropharmacology conference in Paris.
There have been studies looking at the genetic markers and their changes among persons suffering from PTSD in the past. However, designing and conducting such studies has been a challenge in the past. This team of researchers from the Netherlands looked at Dutch soldiers and the Dutch Ministry of Defense to understand the genetic change among these sufferers. This was a longitudinal study wherein the participants are followed up for a period of time. For the study the team collected blood samples before deployment of the participants to the combat zones in Afghanistan and then again at 6 months after deployment. Most of the soldiers included in the study had faced trauma and some of them developed PTSD.
For this pilot study, a total of 24 subjects were selected. Eight of these developed symptoms of PTSD and eight had faced traumatic experiences without developing symptoms of PTSD and the remaining eight had not been in serious traumatic circumstances and did not thus develop PTSD symptoms. The last group served as a control group against which the other two could be compared. Modern sequencing techniques were used to identify the several types of miRNAs in the different groups.
MiRNAs (Micro RiboNucleic Acids) are essentially small molecules with chemical structures similar to DNA. Unlike DNA molecules, miRNAs are generally shorter sequences with only around 20 to 25 base units. They thus do not code for any specific protein or peptide. These miRNA however help in the regulation of genetic expression and thus control the activities of several genes. They also help regulate the impact of environmental factors on the genes. Brain-derived miRNA further are found in blood. The variations in the miRNA levels can be detected in several diseases including major depression, kidney disease, cancers and alcoholism.
The results of the study showed that the individuals with PTSD showed variations in levels of these miRNA. First author Dr Laurence de Nijs from Maastricht University, explained that these small molecules vary in their levels in the blood of persons suffering from PTSD when compared to persons who suffered trauma but did not get PTSD. Over 900 different types of these small molecules were detected he said. 40 of them were regulated in a a different manner in persons with PTSD and 27 were different in persons who were exposed to trauma but did not develop PTSD. Dr. de Nijs added that this study showed that miRNAs might be candidates or markers that could predict who were at a greater risk of developing PTSD after trauma. He hoped that after several rounds of vigorous testing for the robustness of this new technique, this could also pave the way to a better understanding of the mechanism of development of PTSD. Currently, there is no definite cure for patients with PTSD and those with PTSD are at six times more risk of committing suicide and failing interpersonal relationships leading to an annual loss of productivity of an estimated $3 billion.
PTSD
PTSD is estimated to affect about 1 in every 3 people who have faced a traumatic event in the past. It is a form of anxiety disorder caused by a distressing or traumatic life event.
Apart from deployed soldiers who are common sufferers of PTSD, other common risk factors for PTSD include those who have been sexually or physically abused early in life, those who have been a witness to or victim of a serious accident, fire, terrorist attack or natural disaster or violence such as rape, robbery or mugging etc.
According to Dr. de Nijs not all persons who have been through a traumatic event or a psychological stress develop PTSD. The disorder is not caused by more regular stressful life events such as financial bankruptcy, divorce, job change or house move etc.
The symptoms of PTSD may take weeks, months or even years after the event. Usually within 6 months of the traumatic event the symptoms may begin for most. Symptoms of the condition vary between individuals but one of the most common symptoms is experiencing nightmares or flashbacks of the traumatic experience that caused PTSD in the first place. This may lead to other problems including depression, low mood, irritation, difficulty sleeping or concentrating and confusion, despair, guilt and suicidal ideation. The person may always be on guard says Dr. de Njis. The “on” state persists even after the danger has gone. The symptoms may interfere with day-to-day living as well as social and personal relationships. Persons with PTSD are six times more likely to be suicidal. Risk of alcohol and drug abuse is also higher among these persons.
There is no permanent cure for PTSD but the symptoms can be controlled using counselling or psychotherapy such as cognitive behavioural therapy and medications including antidepressants paroxetine and mirtazapine etc.
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