Sunday, November 14, 2010

New treatment for PTSD?

There is encouraging research coming from McGill University in Toronto(correction: Montreal) on the treatment of PTSD. Before I explain the treatment however we must understand some new information on the way in which memory works.

First, situational memory and emotional memory are actually parallel systems that work together, but separately.

Secondly, that the act of recalling a memory is a destructive process which makes the memory unstable and the brain must "reconsolidate" these memories, essentially "rewriting" them back to long term memory. During this process, the memory is subject to being changed, or even deleted. This is the mechanism that is believed to be behind "implanted", or false memories, and also what is behind faulty eye witness testimony. Investigators can inadvertently tamper with a witness's memory of an event and not realize they had done so, by subtly steering a witness inadvertently through leading questions etc.

And third, and this is key to the treatment of PTSD, is that the emotional recollection of the event and the situational or factual recollection of the same event are stored using different parts of the brain using surprisingly different neuro-chemical processes.

PTSD is the inability to emotionally process a traumatic memory because the emotional component of the memory is too painful to process or recall. Emotionally processing these memories requires a grief process. Unprocessed grief leads to all sorts of emotional problems whenever an external or internal trigger causes an unwanted recollection of the unprocessed memory. Until now, the only real treatment offered to those with PTSD is forcing the person to recall the memory over and over again over a period of time in an attempt to force the person to grieve and thereby process the memory, but this has had only limited success because some memories are simply too devastating emotionally to process, no matter how often the person is forced to recall it, and may in fact traumatize the patient even more.

But what if you could reduce the emotional content of the memory without changing the situational or factual part of the memory? This is the key to the new treatment. Since the two memory systems are separate and parallel, it is possible to alter one without changing the other. Neuroscientists at McGill have discovered that the emotional part of the memory is processed by the amygdala and is dependent on adrenaline, and subsequently it's effects on norepinephrine, for the memory to reconsolidate. Adrenaline however does not appear to have a significant role in the reconsolidation of the factual or situational memory of the same event.

This has lead to two new treatments for PTSD that have shown great promise.

First to prevent PTSD in the first place, it has been found that there is a short window after the initial traumatic event where the administration of opiates (morphine/demerol/etc.), Beta-blockers, or benzodiazepines (librium/valium/etc.) immediately after the event prevents the initial consolidation of the traumatic anxiety.

Secondly, that dosing the patient with a drug that interferes with adrenaline just prior to having the patient recall the traumatic memory interferes with the reconsolidation of the emotional anxiety associated with the memory, leading to a greatly reduced anxiety level on subsequent recollections. repeating the treatments further reduces the anxiety level. Such a drug happens to be the lowly beta blocker blood pressure medication propranolol, which has been used since the 1950's.

Ironically, this research has not made wide in-roads in the treatment of PTSD, even though it has been ongoing for some time. The reason would appear to have it's roots in the biases that psychologists have for "talking treatments" over pharmacological ones. Let us hope that this bias falls to a desire to do what is best for the patient instead of what is best for the therapist's ongoing income stream.

Further Reading:

Memory Reconsolidation and Treatment for Post-Traumatic Stress (PTSD)

The Effect of Childhood Trauma on Brain Development

When Remembering Might Mean Forgetting

2 Comments:

Anonymous Anonymous said...

I saw your blog link on the Baltimore Sun article about "erasing memories." The study you're referring to is Alain Brunet's - I wrote him earlier this year about obtaining a copy of his study. One of his aides emailed me back a pdf of the original (smaller) study - would you want a copy?

November 23, 2010 5:36 AM  
Blogger Rorschach said...

Sure, I'd love a copy! Just email it to redinktexas@gmail.com. And thanks!

November 23, 2010 7:16 AM  

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