Trauma is a very real problem in today’s society. We live in a violent world, and many people are subjected to violence on a daily basis. This may be because of wars, gang violence, domestic abuse, or simply being ‘different’.
Although the physical effects of violence have been known for hundreds of years, it wasn’t until World War 1 and the emergence of ‘shell shock’ that the impact of trauma on mental health became public knowledge. Even then, however, shell shock was viewed as a weakness, and it’s sufferers as cowards and ‘lesser men’.
Since then our understanding of trauma has developed, and we now know that shell shock is a very real mental health problem. Now known as Post Traumatic Stress Disorder it is viewed as a mental health problem just like depression or psychosis. There are very effective treatments for PTSD such as Cognitive Behavioural Therapy (CBT) and Eye Movement Desensitisation and Reprocessing (EMDR). Despite our enlightenment since World War One, however, there are still many things about trauma which we don’t understand. For instance, we don’t know why trauma only effects some people very negatively (i.e. leads to PTSD) rather than all people.
Recent research, however, suggests that there may be an underlying genetic determinant of the stress-response. Yehuda et al (2015) analysed the genes of 32 holocaust survivors and their offspring (22 people) and compared these to the genes of a control group who did not suffer the trauma of the holocaust. The researchers were specifically interested in assessing cytosine methylation of the gene called FKBP5 which responsible for the production of (encoding of) FK506-binding-protein-5, a protein that has been associated with a heightened stress response (e.g. Touma et al, 2011) . Cytosine methylation is a process whereby DNA is modified to alter gene expression. In lay terminology, this means the gene is given a ‘tag’ which tells the gene to turn on or off.
When the researchers compared the two groups of participants, it was found that the holocaust survivors and their children had ‘epigenetic tags’ on these genes which were not found on the genes of the control group. This suggested that something about the holocaust experience altered the genetic expression of the holocaust survivors, and this change was passed down to their offspring. They can then determine that it was the stress of the experience because FKBP5 is known to have a significant role in emotional disorders, and particularly PTSD. Complex analysis also allowed the researchers to rule out childhood trauma as the reason for the genetic change in the holocaust survivor’s offspring.
This research is ground breaking as noted by Dr Yehuda:
“To our knowledge, this provides the first demonstration of transmission of pre-conception stress effects resulting in epigenetic changes in both the exposed parents and their offspring in humans.”
It completely throws into question what we thought we knew about how genetic information is passed from parent to offspring. It was previously thought that these genetic tags could not be passed on through the generations as DNA from reproductive cells (i.e. sperm and eggs) was in effect ‘wiped clean’ as soon as fertilisation occurs. This research calls in to question this theory, and highlights the need for further investigation.
What does seem clear, however, is that suffering a trauma is not only a life-changing and mind-altering problem for a victim to deal with, but it can also go on to impact the mental health of that individual’s offspring. As this is the first study of it’s kind, we have no knowledge of exactly how much of an effect this phenomenon will have on the children of trauma victims. It may well only have a small impact on the stress response, but it is equally possible that it could predispose these offspring to developing affective disorders such as PTSD, anxiety and depression, and they may even pass these genetic changes on to their own children.
It will be both enlightening and necessary to investigate this phenomenon further over the next few years, and I am eagerly awaiting follow-up research.