What trauma leaves behind

Trauma impacts mental health especially trauma in childhood.  In a previous blog post I wrote about how kids who are poor are more likely to be exposed to trauma than wealthy kids.  Now there is research that indicates that the effects of trauma can be biologically transmitted across generations.  The researchers subjected mice to trauma in the laboratory in the form of electrical shocks.  When baby mice were conceived using the sperm of the traumatized mice, the babies had a stress reaction to stimuli that were associated with their parents trauma, in this case a particular smell, and the effects seem to stretch over several generations.  The theory put forth by the scientists to explain this is epigenetics, that certain genes are 'turned on' or 'off' by experiences creating heritable traits as a result of what happens in the environment. 

If this carries over to humans, it could mean that a kid whose grandmother or grandfather experienced trauma could still carry the impact of that trauma in his or her body.  My clinical experience is that trauma does seem to pile up in families.  Sometimes the people who come into my office will describe three generations of abuse.  It can be hard to get out from under that.  Now we have another indicator of why that might be the case.  Not only can there be a cultural inheritance of trauma in a family, the genetics of one's descendents can be marked by traumatic experiences. 

On a more hopeful note, epigenetics may work to undo some the hurt of previous generations.  Researchers here in Montreal, at the Douglas Hospital, have looked at the effect on an epigenetic level of nurturing by a parent on mediating stress (more traumatized rodents).

Baby rats that are licked often by their mothers—with licking in rats fulfilling the same function as cuddling in humans—are calmer than rats that are not licked enough. Michael Meaney and his team delved further into this idea by tracking the imprint left by maternal care in the brain of young rats. They were able to do this because the action of licking influences the activity of a gene (called NRC31) that protects rats against stress; when activated, this gene produces a protein that helps decrease the concentration of stress hormones in the body. A specific part of this gene must also be activated via an epigenetic switch.
— http://www.douglas.qc.ca/info/epigenetics

According to this theory loving cuddling can help kids deal better with stress than they might even if they have an epigenetic inheritance of trauma.  So why are you still reading?  Go hug your kids. 

Extinction is good for you.

Why do most people bounce back from a traumatic experience after a few weeks or months when others struggle for years with anxiety or PTSD?  What protects some people from the effects of trauma?  What can we do to promote resiliency from trauma? The answer might have to do with 'extinction.'

In psychological parlance 'extinction' can be a good thing.  Extinction means 'unlearning' a conditioned response.  Remember Pavlov and his dogs?  Ring the bell and feed the dogs, eventually the dogs will salivate at the sound of the bell.  That is conditioning.  Well, after a while if they get their food without the bell, the conditioning wears off and the dogs don't salivate anymore, and that is extinction learning; learning that something that was once associated with an experience may not be connected to that experience.

Maladaptive trauma responses, including disorders like PTSD, probably have something to do with conditioned response.  People with PTSD may associate all sorts of things with the original trauma so they are triggered to re-experience the trauma by a smell or sound, or they seek to avoid being in situations which call to mind the trauma, even though objectively those circumstances aren't dangerous.  Richard Bryant, a researcher into responses to trauma, has done a really smart prospective study that suggests that a person's pre-trauma capacity for 'extinction learning', his or her ability to 'unlearn' the connection between a negative experience and the circumstances surrounding it, is very predictive of the ability to bounce back from trauma.  He describes it at about 31 minutes of this video.  The whole video is interesting but this piece is only about four minutes.  

Here's the study for those of you interested in checking it out.  Bryant doesn't talk about what predisposes people to be better or worse 'extinction learners.'  Some of it probably has to do with genetic factors.  I would be curious to know to what degree cognitive flexibility, the ability to change one's ideas about the world, correlates with extinction learning.  Cognitive flexibility can be enhanced by all sorts of things.  If you want to test your cognitive flexibility, some of these tests, like the Stroop test, are good measures.  In the interests of full disclosure I did pretty badly on the Stroop test.  Not sure what that means for my chance of extinction.