Alterations in blood-based miRNA in veterans affected with combat-related PTSD

September 4, 2017, European College of Neuropsychopharmacology
PTSD
Regions of the brain associated with stress and posttraumatic stress disorder. Credit: National Institutes of Health

Individuals affected with PTSD (Post-Traumatic Stress Disorder) demonstrate changes in microRNA (miRNA) molecules associated with gene regulation. A controlled study, involving military personnel on deployment to a combat zone in Afghanistan, provided evidence for the role of blood-based miRNAs as candidate biomarkers for symptoms of PTSD. This may offer an approach towards screening for symptoms of PTSD, and holds promise for understanding other trauma-related psychiatric disorders. Limitations of the study are that this was a small pilot study, and the findings need to be validated, extended and confirmed. First results will be presented at the ECNP conference in Paris.

PTSD is a psychiatric disorder which can manifest following exposure to a traumatic event, such as combat, assault or natural disaster. Among individuals exposed to traumatic events, only a minority of individuals will develop PTSD, while others will show resiliency. Little is known of the mechanisms behind these different responses. The last few years have seen much attention given to whether the modification and expression of genes - epigenetic modifications - might be involved. But there are several practical and ethical challenges in designing a research study on humans undergoing such experiences, meaning that designing relevant study approaches is difficult.

The research group from the Netherlands, worked with just over 1,000 Dutch soldiers and the Dutch Ministry of Defense to study changes in biology in relation to changes in presentations of symptoms of PTSD in soldiers who were deployed to combat zone in Afghanistan. In a longitudinal study they collected blood samples before deployment, as well as 6 months after deployment. Most of the soldiers had been exposed to trauma, and some of the soldiers had developed symptoms of PTSD.

For this pilot study, from the initial group, subgroups were selected of in total of 24 subjects; 8 of the soldiers had developed symptoms of PTSD; 8 had endorsed traumatic experiences but had not developed symptoms of PTSD; and another 8 had not been in serious traumatic circumstances and served as a control group. Using modern sequencing techniques, several types of miRNAs of which the blood levels differed between the groups were identified.

MiRNAs (Micro RiboNucleic Acids) are small molecules with chemical building blocks similar to DNA. Unlike the more famous DNA, miRNAs are typically very short - comprising only around 20 to 25 base units (the of nucleic acids), and they do not code, in other words they do not specify the production of a protein or peptide. However, they have very important roles in biology (every miRNA regulates the expression, and thereby also the activity of several other genes), and they are known to regulate the impact of environmental factors on biology. In addition, brain-derived miRNA can circulate throughout the human body and can be detected in the blood.

Differences in miRNA levels have been associated with certain diseases, such as some cancers, kidney disease, and even alcoholism. This regulatory role makes them also a candidate for investigation in PTSD.

"We discovered that these small molecules, called miRNAs, are present in different amount in the blood of persons suffering from PTSD compared to trauma-exposed and control subjects without PTSD", said first author Dr Laurence de Nijs (Maastricht University).

"We identified over 900 different types of these small molecules. 40 of them were regulated differently in people who developed PTSD, whereas there were differences in 27 of the miRNAs in trauma-exposed individuals who did not develop PTSD."

"Interestingly, previous studies have found circulating miRNA levels to be not only correlated with different types of cancer, but also with certain psychiatric disorders including major depressive disorders. These preliminary results of our pilot study suggest that miRNAs might indeed be candidates as predictive blood markers (biomarker) to distinguish between persons at high and low risk of developing PTSD. However, several steps need to be performed before such results can really have an impact on the larger field and in clinical practice. In addition to working towards biomarkers, the results may also provide novel information about the biological mechanisms underlying the development of PTSD".

Dr de Nijs explained:

"Most of our stressful experiences don't leave a long-lasting psychological scar. However, for some people who experience chronic severe stress or really terrible , the stress does not go away. They are stuck with it and the body's stress response is stuck in 'on' mode. This can lead to the development of mental illness such as PTSD.

These individuals experience symptoms including re-experiencing of the traumatic event through flashbacks or recurrent nightmares, constant avoidance of reminders of the event, negative mood, and extreme arousal. This can manifest itself through insomnia and or hyper-alertness. Individuals with PTSD are six times more at risk of committing suicide and having marital problems, and the annual loss of productivity is estimated to be approximately $3 billion. Currently, there is no definite cure for patients with PTSD, and available treatments often are not effective".

Commenting, Professor Josef Zohar (Ex-ECNP Chair, Tel Aviv, Israel) said:

"The relevance of a better understanding of stress related events is unfortunately becoming clearer and clearer after each terror attack. This work points to an innovative avenue regarding the potential identification of risk factors for susceptibility to developing post-traumatic stress disorder".

Explore further: Some patients with dementia may experience delayed-onset PTSD

Related Stories

Some patients with dementia may experience delayed-onset PTSD

July 7, 2017
Delayed-onset post-traumatic symptoms in the elderly may be misdiagnosed as falling under the umbrella of behavioural and psychological symptoms of dementia (BPSD), according to a recent review.

PTSD may be physical and not only psychological

July 11, 2017
The part of the brain that helps control emotion may be larger in people who develop post-traumatic stress disorder (PTSD) after brain injury compared to those with a brain injury without PTSD, according to a study released ...

Study finds first molecular genetic evidence of PTSD heritability

April 25, 2017
A large new study from the Psychiatric Genomics Consortium provides the first molecular genetic evidence that genetic influences play a role in the risk of getting Posttraumatic Stress Disorder (PTSD) after trauma.

PTSD risk can be predicted by hormone levels prior to deployment, study says

March 7, 2017
Up to 20 percent of U.S. veterans who served in Iraq and Afghanistan developed symptoms of post-traumatic stress disorder from trauma experienced during wartime, but new neuroscience research from The University of Texas ...

Parents don't notice children's PTSD, may need support themselves

November 8, 2016
Young children may experience Post Traumatic Stress Disorder (PTSD) for years without it being recognised by their parents according to new research from the University of East Anglia (UEA).

Study reveals areas of the brain impacted by PTSD

January 23, 2017
Researchers at Boston University School of Medicine (BUSM) and the VA Boston Healthcare System are one step closer to understanding the specific nature of brain changes associated with Posttraumatic Stress Disorder (PTSD).

Recommended for you

Researchers replicate famous marshmallow test, makes new observations

May 25, 2018
A new replication study of the well-known "marshmallow test—a famous psychological experiment designed to measure children's self-control—suggests that being able to delay gratification at a young age may not be as predictive ...

Can we really tell if it's love at first sight?

May 25, 2018
Long-term and short-term relationships are obviously different from each other. Some people are the type you'd want to marry; others are good primarily for the sex.

People with family history of alcoholism release more dopamine in expectation of alcohol

May 23, 2018
People with a family history of alcohol use disorder (AUD) release more dopamine in the brain's main reward center in response to the expectation of alcohol than people diagnosed with the disorder, or healthy people without ...

Why we fail to understand our smartphone use

May 23, 2018
Checking your phone dozens of times a day indicates unconscious behaviour, which is "extremely repetitive" say psychologists.

Study confirms that men and women tend to adopt different navigation strategies

May 23, 2018
When navigating in a known environment, men prefer to take shortcuts to reach their destination more quickly, while women tend to use routes they know. This is according to Alexander Boone of UC Santa Barbara in the US who ...

Early life trauma in men associated with reduced levels of sperm microRNAs

May 22, 2018
Exposure to early life trauma can lead to poor physical and mental health in some individuals, which can be passed on to their children. Studies in mice show that at least some of the effects of stress can be transmitted ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.