PTSD has been shown to be one of the most debilitating conditions
to live with, considering the constant re-experiencing of the trauma and the
inability to cope with future stress.
There are now studies to show that PTSD may in fact be genetically
passed on to the children of PTSD sufferers.
It is generally believed that there were 3 main factors that
contributed to a person’s likelihood of developing PSTD. A person’s predisposition to develop
psychiatric illnesses, a person’s life experiences and traumas, and a person’s
temperament are all contributing factors.
With this new research comes a new debate: is the condition
really passed down through the genes, is a predisposition passed down, or is
the condition “taught”?
Rachel Yehuda did the first research with survivors of the
Holocaust. It was believed that those
who survived would present with symptoms of PTSD, although there was not yet a
diagnosis as such. The research was conducted on the children of these survivors
to see whether they exhibited any symptoms, compared to the control group of
people their age from non-PTSD parents. The studies showed that there were
higher levels of Cortisol, the stress hormone, in the children of the PTSD
parents. The children of the PSTD parents were shown to have trouble coping
with stress, but didn’t show any significant differences in self-esteem or
psychopathology. The research further showed that the more severe the PTSD in
the parent was, the more severely the Cortisol levels in the children were
affected.
In further support of the heritability of PTSD an experiment
was conducted where a generation of male mice were taken away from their
parents at continuous but unpredictable intervals, until the age of 14
days. Thereafter, their mother raised
them normally. This separation was seen
as an early trauma and for the purpose of the experiment, these mice were then
considered to be the equivalent of the 1st generation Holocaust
survivors. These mice then had litters
of their own which were raised without the trauma their male parent
experienced. These mice were considered to be the equivalent of the children
and grandchildren of the Holocaust survivors.
These mice, however, showed the same symptoms as their traumatized parents;
isolation, jumpiness, skittishness and hyper vigilance. Examination of the
father and offspring mice showed that all the genes that deal with stress were
either over-active or under- active.
These genetic changes had been transferred to the offspring of the original
trauma-affected male mice. This study
showed that traumatic stress may alter the regulation of genes in the germ line
cells in males, meaning that the stress effects may be passed across
generations.
More recently, there has been the discovery of a specific gene,
which could be responsible for PSTD. The
D2A1 allele genetic anomaly has been shown to determine the effectiveness of
the D2 receptor (dealing with Dopamine), which can predict the onset of PSTD.
The idea of epigenetics was then introduced. This is the change in the expression of DNA due to environmental
factors, not an actual change in the DNA. Blood samples taken from PTSD patients had 6
to 7 times the number of abnormalities in the function of genes in comparison
to those not suffering from PTSD. In the offspring of PTSD sufferers, the
epigenetic changes lead to reduced sensitivity. They showed constant hyper vigilance, as if
their bodies had been programmed into thinking that the world was simply too
dangerous a place to ever relax.
On the opposite side of the scale, there are those who
believe that the PTSD is passed on to the next generation by “teaching”. It is very likely that parents who are
suffering from PTSD are hyper vigilant, jumpy, neurotic, isolated and have a
negative world-view. If a child is
raised in this environment, it can be expected that the child will learn some
of these habits and also begin to exhibit the symptoms of a PTSD sufferer.
It would seem though, that a combination of the above
theories makes the most sense. One study
divided the children of PTSD sufferers into two groups, the post-trauma
children, children born after their parent/s had experienced a severe trauma,
and the pre-trauma children, who were conceived before their parent/s had
experienced a severe trauma. It was decided that the post-trauma children that
displayed the symptoms of PSTD had both inherited the genetic abnormalities as
well as learnt the symptoms from their parents.
The pre-trauma children that displayed PTSD symptoms could only have
learnt them from their PTSD parent/s. Both groups did display symptoms of PTSD
and so a combination of the two theories seems to be reasonable.
It is frightening to think that one could suffer from the
symptoms of PTSD without having experienced a severe trauma, but ultimately
that’s all it is; the symptoms. One
cannot be diagnosed as suffering from PTSD without the presence of a serious
traumatic event. This is according to
the DSM-IV. So it would be fair to conclude that one can inherit genetic
abnormalities from PTSD parents, inherit a predisposition to PTSD with a PTSD
prone personality as well as learn the symptoms from a parent. However, it is
not possible to actually inherit the PTSD, by its current definition.
