Friday, June 4, 2010

PTSD: Prevention -- Sort Of


Readers will know that I am firmly in the camp that calls for  the "trauma" in Post-Traumatic Stress Disorder to include more than war and rape.  Nevertheless, as I write this third in my PTSD series on Memorial Day weekend, I write with love, honor and respect for my parishioners, friends and family members who have served this nation in combat.  As it happens, all of my people have come home.  But none of them ever really.

Now know this.  It frames the whole conversation about research into prevention of Post Traumatic Stress Syndrome.  All the efforts currently being studied and tried for prevention are about preventing PTSD in those who have already experienced trauma.  (That's called "secondary prevention.")  They are not about preventing the trauma in the first place.  Read it again and remember that point.  I shall return to it.

[If you want to skip the research, you can scroll down from here to the **** where I take up my conclusions.] 

A number of medications are being tried post-trauma (the "morning-after" pill) to interrupt stress mechanisms and to impede the particular memory consolidation that leads to PTSD.  If memories of the trauma, including sights, sounds, smells, sensations are not associated with the conditioned fear response, then triggers will not elicit symptoms and PTSD will be prevented.

One strategy is to damp down the activity of the adrenal gland.  Propranolol is a prime candidate for this use.  It is used now to treat hypertension and anxiety disorders, because it reduces the fight or flight mechanism, the release of catecholamine from the adrenal gland and speeding up of the heart rate, among other things.  Propranolol interferes with the memory of emotional events, because the mental image is not "consolidated" with the bodily experience of adrenaline.

Studies of propranolol have been conducted on trauma victims.  Usually it is administered in the emergency room, within a few hours of the trauma, and then continuing over the course of several days.  The results are mixed.  In some studies, those who received the medication experience fewer PTSD symptoms one or two months later.  A NIMH study in 2007 did not replicate these results.

Another approach is to address the damage done farther downstream, by changing the balance of neurotransmitters.  Neurotransmitters sit in the space between brain cells (called synapse) and help messages move along from one to the other.  Serotonin (of Prozac fame) carries the messages and is the best known by the general public, but there are several others, as well.

Glutamate is a neurotransmitter that speeds up the action between brain cells.  There is a lot of glutamate in the hippocampus, where it helps develop long-term memory.  GABA slows down the passage of messages, which gives it a tranquilizing effect on glutamate.

The balance of these two affects the health of neurons.  Persons with PTSD have more glutamate and less GABA on board than those without PTSD.  The Defense Department is currently funding a study to discover whether an intervention to redress the balance might make communication between brain cells less efficient -- again, interfering with the consolidation of long term memory.

Another option is an earlier and more aggressive use of serotonin.  Serotonin supports brain-derived neurotrophic factor (BDNF).  So it indirectly helps the brain repair itself, reversing shrinkage in the hippocampus.

The neurotransmitter Neuropeptide Y (NPY) inhibits the release of stress hormones norepinephrine and corticotropin releasing factor.  There is some evidence that enhancing the production of NPY might reduce the problems caused by stress overload.  But there are no such medications available yet.

Then there are the opiates, such as morphine.  It would be unethical to conduct the typical research using morphine, i.e., giving the medication to one group and placebo to another.  This January, the New England Journal of Medicine reported an "observational study" of morphine use in the battlefield.  The medical records of 696 injured military personnel were examined after treatment.  Those with moderate or severe traumatic brain injuries were excluded from the study, because severe brain damage protects against PTSD.  How's that for irony.

The study concluded that morphine does provide some protection against PTSD.  Among the patients in whom PTSD developed, 61% received morphine; among those in whom PTSD did not develop, 76% received morphine.  The odds of this difference occurring by coincidence are less than one in a thousand (odds ratio, 0.47; P<0.001 in statistics-speak.)  Severity or mechanism of injury, age and amputation -- none of these factors made a significant difference in the findings.

It is speculated that morphine has this protective effect because severe pain increases the trauma of the injury, and hence of the memory.  I wonder if it might prove more effective in nonmilitary use, among those whose brains are not being primed for PTSD every single day.

Okay, the limitation of any of these medications is that they are directed at single event traumas, rape, injury, one time devastating experience.  The brains of soldiers and abused children are injured and prepared for PTSD daily.  What are we going to do, sprinkle propanolol into the cornflakes of everybody deployed in a battle zone, make it part of school lunches?

There are also more creative, nonpharmocological approaches being explored.  Louisiana State University Health Sciences Center is going to study hyperbaric oxygen treatment for those with traumatic brain injuries. TBI has been called the signature wound of the wars in Iraq and Afghanistan. A RAND Corporation study released in April estimates that about 320,000 service members may have experienced a traumatic brain injury during deployment. 

In hyperbaric oxygen treatment, burn and carbon monoxide victims are placed in a pressure chamber to increase oxygen in the blood stream, and hence in the brain.  Think of deep breathing to relieve your anxiety attacks.  LSUHSC will compare TBI victims who receive or don't receive this treatment, in hopes of discovering a new approach to help this subset of injured soldiers.

Like the medications, hyperbaric oxygen treatment (if it works) will be given to those with one time traumas, not so useful for continuing trauma.  Here is another approach that might work on a daily prophylactic basis.  Tetris!

An admittedly small study conducted at the University of Oxford examined whether "visiospatial cognitive stimulation" could provide a vaccine against flashbacks.  It was based on the capacity of the brain to process just so much stimulus at one time.  If that capacity is used up by the intrusion of non-traumatic images, then perhaps the traumatic ones would be encoded in memory less deeply. 

So they showed the Trauma Film, a twelve minute piece that is known to produce flashbacks.  After thirty minutes, ten subjects played Tetris, and ten sat quietly.  Tetris was chosen because it is known to intrude upon image-based memory (people see images of the game at a later time after playing).

In fact, these intrusive memories are why I stopped playing it.  It was additively soothing, but I kept seeing the Tetris shapes around me in everyday objects.  Like, the silhouette of a head and shoulders became that L-shaped piece.  At one point I asked my young son to hide his game-boy, so I couldn't find it!  Now I play other games that intrude on image-based memory.

I digress.  Anyway, in the following week, the Tetris-playing group had fewer flashbacks to the Trauma Film than the others.

Now this is an application that could be used in the battlefront.  I understand that soldiers often play computer games when they return to base, though usually they are war games.  Tetris or maybe some other matching three type game could push the day's images out of their brains.

***********

Okay now, I have spent months gathering these studies of secondary prevention of PTSD, and struggling with two issues regarding the vast numbers of new sufferers of PTSD who are created every day in Iraq and Afghanistan.

The first is a dilemma.  After we have put our young people in harm's way, after they have been injured in the service of their country, surely they need -- and deserve -- the best medical care we can give them.  And better.  Surely we need to do more research for better medications and better treatments.

What troubles me is that the medications and treatments are designed to obscure from them the horror of their experiences.  While we treat them, we are creating more effective soldiers, soldiers who can do more and more terrible things, because we have undone part of their most human response to these terrible things.  And we are creating in ourselves denial about what war is.  The healthy human being would go crazy.

And we can't do this so selectively as we would like.  When we interfere with the consolidation of traumatic long term memories, we also interfere with all long term memories.  Which, ironically, is what PTSD does.  Part of how the brain protects itself from horror is to go numb to all feeling.

And yet, their suffering is real and urgent.  How can we not relieve their pain by any means possible?

See what I mean?

My second issue is this.  All the medications and treatments I have described are secondary prevention. -- I said at the beginning that I would return to this point.

What is primary prevention?  It's what we do with lung cancer.  We don't invent treatments that intervene between inhaled carcinogens and the lungs.  We conduct public campaigns against smoking.  We don't make the liver more efficient in processing poison.  We prohibit the use of lead-based paint.  We don't prevent Froot Loops and the sugar in even salad dressing from overwhelming the pancreas and kidneys.  We educate about high fructose corn syrup and our epidemic of diabetes and obesity.  -- Okay, there's a little hypocrisy in that last one, when we compare the money spent on health education to the subsidies given to produce high fructose corn syrup.

What about primary prevention of PTSD?

When is the Surgeon General of the United States of America, Vice Admiral Regina M. Benjamin going to stand up and tell us the truth -- that war is a health hazard?

The frontal cortex of the human brain, the part that comprehends the consequences of actions, is not fully developed until age 25.  When are recruiters going to be banned from high schools and college campuses and malls?  Or federal funding refused to schools that permit ROTC programs?  When are those ads for the Marines going to be banned from the Super Bowl and other sporting events?  When are parents going to teach their children, Just say no?

Defense Secretary Robert Gates said recently that leaving aside “the sacred obligation we have to America’s wounded warriors, health care costs are eating the Defense Department alive.”  Imagine how much money we could save is we stopped putting them in harm's way.

Before automated warning systems were developed, coal miners used to take canaries with them into the mine.  When the canary died, the miners knew the air was poisonous.  It was time to get out of the mine.

So here is the last thing I am going to say about PTSD for a while:

We gotta lot of dead canaries.  When will we get out of the mine?


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