Lethe In A Pill

Throughout history and across cultures, the force of memory has always held a prominent position in our concept of humanity and self.  The ancient Greeks embodied memory in a goddess – Mnemosyne, the mother of the nine inspiring Muses.  But what if a person possessed memories so upsetting and intense that they caused him to not be able to function as himself?  If you had the option, would you choose to forget or to distance yourself?  This dilemma is now a source of debate among scientists and medical practitioners.  Propranolol, a drug previously prescribed to people suffering from hypertension, has also been found to bring some relief to victims of traumatic events by manipulating their memory of the experience.

When a person experiences a highly emotional or traumatic event, their memory of it is far more vivid than that of a mundane occurrence.  We tend to think of such moments as something to treasure, or a defining experience that, even if painful, contributes to who we are.  However, there is also a biological reason for the strength of such a memory.  While a person feels heightened emotions, the sympathetic nervous system causes the adrenal glands to release epinephrine (adrenaline) and other stress hormones that enter the blood stream and contribute to the physical symptoms of fear - wide eyes, sweating, fast pulse, and dilation of blood vessels in larger muscles (6) - as well as reactions in the amygdala and hippocampus (two parts of the brain responsible for memory).  “Stress hormones activate adrenergic receptors in the basolateral amygdala, which modulates the effect of these hormones on hippocampal consolidation [of memory]” (7).  The amygdala deals with responding to emotional stimuli, especially fear, by enhancing perception, and sending information of that nature to the hippocampus.  The hippocampus is the part of the human brain that seems to be in charge of forming short and long term memories.  “By influencing perception and attention, the amygdala can alter the encoding of hippocampal-dependent, episodic memory, such that emotional events receive priority” (7).  Essentially, memories that involve strong emotional stimuli, through the interaction of the sympathetic nervous system, the amygdala, and the hippocampus, are more intensely imprinted onto the human mind in “neurological ink” (5).  

Posttraumatic stress disorder (PTSD) is a condition that some victims, survivors or witnesses of horrific experiences may develop when their memories are too intense – when the amygdala made them too powerful.  PTSD is characterized by flashbacks so vivid the patients are essentially reliving the moment(s) that caused the trauma.  These “often return relentlessly for years, evoking the same fear, helplessness, horror and consequent anguish that accompanied the initial experience.  This creates a disabling cycle that can be difficult, if not impossible, to break” (1).  Some patients also suffer from detachment from loved ones, and sleep problems such as nightmares or insomnia (4).  Every time a PTSD patient experiences a flashback, the memory is strengthened by stress hormones pumping through the brain again – rather like reviewing emotionally intense flash cards (1). There are different degrees of PTSD as with any other illness.  About eight percent of the population of the United States will suffer from PTSD in their lifetime, and it is twice as probable for women to develop the condition (5).  Seeking therapy from psychiatrists has been effective for some patients, but is viewed as insufficient by others.  However, more opportunities for treatment may be on the horizon with the research being conducted by scientists on a beta-blocker drug called propranolol.

         Previously, propranolol has been used successfully to treat hypertension.  Recent research has shown that beta-blockers prevent some stress hormones like epinephrine from being released onto the memory forming parts of the brain such as the amygdala and hippocampus (5).  Similarly, their effects as hypertension drugs – decreasing heart rate and others – also lessen the physical effects of emotional stress (4).  As a result, patients would not forget the traumatizing event, but the memory of it would be less powerful.  As psychiatry professor Roger K. Pitman of Harvard Medical School states, propranolol would “reduce the intensity of the memories to a more normal level, a level that a person can easily live with” (2).  By inhibiting the chemical stimuli that accompany emotion, the memory is recorded as mundane rather than extraordinary or disturbing and becomes vulnerable to the potential cloudiness that causes a person to forget what they did with their keys. 

There have been many studies conducted on the effects of propranolol on the formation of memory.  One very telling study was done in 2001 by Dr. Pitman.  Forty-one trauma patients in the Massachusetts General Hospital were randomly prescribed ten days’ worth of propranolol or a placebo within six hours of their injuries – mostly car accidents.  After one month, the patients who remained with the study were evaluated.  The difference between the scores of the two groups “was not statistically significant” (3), but only two out of eleven of the propranolol patients were diagnosed with full blown PTSD, where as six out of twenty of the placebo patients were found to have developed it.  Three months later, remaining participants “listened to their own taped verbal descriptions of the trauma and then imagined the event for 30 seconds”.  Six out of fourteen of the placebo patients responded physiologically to reviewing the experience, but none of the propranolol patients were affected.  These results show that receiving beta-blockers after a traumatic experience does make a difference in the “psychophysiological response to trauma” (3). 

This is not to say, however, that propranolol is ready to be prescribed.  There are still questions pertaining to, among other things, the time frame in which the drug must be taken in order to be effective.  Dr. Pitman’s application of the beta blocker appears to have been successful, but if a memory is reinforced every time it is reviewed, could some patients need a long term prescription?  If the initial response is blocked, is it possible to experience a delayed one?  Taking propranolol soon after an event occurs may head off the initial emotional attachment and engraving of the deeper memory, but it is each individual’s choice whether he or she is going to attempt to recall the memory or let it fade; just as some people continually remind themselves where they put their keys, and others decide they will just find them later.  Similarly, some people are better able to cope with emotionally intense situations and let them go, where as others are more affected – could doctors be giving a drug to an individual who would not have needed it?

There are clear therapeutic possibilities, but is such dampening of emotion really a good or ethical idea?  Hypertension patients have been experiencing the memory altering effects of propranolol without significant complaint (4).  Whether a person chooses to hold onto the memory or try to ignore it is his or her own decision.  David Speigel, Stanford psychology professor, states that “the real task is to refind yourself in the wake of the trauma, not pretend it did not happen” (4).  In some circumstances a vivid memory or rush of adrenaline are valuable If not essential, such as the testimony of a rape victim or a soldier’s will to fight and survive. There is also a risk of desensitization to horrible things – “falsifying our perception and understanding of the world” (5).  In that statement and others, the President’s Council on Bioethics has cast its vote in the negative, being very wary of the repercussions and implications of the use of memory altering drugs (5).  Trying to take a fast track to recovery would disrupt the normal psychological process and perhaps lessen the human sense of empathy, and “diminish our character or our personal development” (5).  On the other hand, scholars like Dr. Pitman postulate that “most people who have PTSD are so debilitated, they would prefer to have their memories tinkered with” (1).  Others say that they do not want to let speculation or legal concerns prevent them from helping a suffering patient.     

Personally, I am torn on the issue, and have an understanding of both arguments.  I place an extraordinarily high value on memories, in relation to my own concept of self, life, happiness, perspective and wisdom, as well as to my interest in history and its continued relevance.  I agree with President’s Council member Dr. William B. Hurlbut’s statement that “the pattern of our personality is like a Persian rug.  It is built one knot at a time, each woven into the others.  There’s a continuity to self, a sense that who we are is based upon solid, reliable experience” (5).  I believe that your memories are the only things that are truly yours.  They shape how you view the world, and define who you are as a sum of all of your choices, actions, thoughts, behavior, and values.  I also ascribe to the idea that what doesn’t kill you makes you stronger.  All of these things would lead me to say that I would never wish to diminish any of my memories. 

However, my situation is not that clearly cut.  Between the ages of one and a half and six I had to go through a series of painful and traumatic medical tests, as well as a kidney operation when I was five and a half.  I still carry the physical scars, and battle with the emotional and mental ones fourteen years later.  The memories still inspire irrational fear and a sense of revulsion that can mentally incapacitate me for a period of time if I am not able to drive them out fast enough, and can be sparked by hearing a phrase or catching sight of any of an ever changing wide range of objects.  Rather than feeling detached from others, I have an extreme sense of empathy, but I do have to deal with friends and loved ones asking why I’m so “psychotic” about my scars.  I went to therapy after the procedure, and have gotten over several related fears, but the deepest, most central fear persists.  I haven’t been tested for it, but I can understand the hardships endured by those who’ve been diagnosed with full blown PTSD. 

My life, like theirs, would be much easier without the chronic sting of memories that you wish would stay dormant in the farthest part of your mind.  Despite my feeling that working through the fears, and living with the memory has made me stronger and contributed greatly to who I am, my most frequent method of dealing with the physical scars is to pretend that they aren’t there and hope that I am not reminded.  That being said, I am tempted to wish a drug like propranolol had been available when those memories were being made.  There have been many times when I’ve wished for the soothing waters of the Lethe, but when I regain my senses I take it back, and determine that the relief is not worth the potential changes to my Self.  I continue to be of that opinion, but it will always be a somewhat unstable one. 

1. http://www.harvardmagazine.com/on-line/070467.html“Cushioning Hard Memories” an article on PTSD and propranolol.

2. http://www.hno.harvard.edu/gazette/2004/03.18/01-ptsd.html “Pill to calm traumatic memories: Puts the mind’s storehouse in order” an article on PTSD and propranolol.

3. http://www.neuropsychiatryreview.com/march02/ptsd.html “Can Beta Blockers Prevent PTSD? A First Look” another article on PTSD and propranolol.

4. http://daily.stanford.edu/article/2004/4/15/whatIfYouCouldEraseYourMemory“What id you could erase your memory?” an article focusing on the controversy.

5. http://www.cognitiveliberty.org/neuro/memory_drugs_sd.html “Blanks for the memories: Someday you may be able to take a pill to forget painful recollections” a thorough and interesting article from the San Diego Union Tribune.

6. http://webspace.ship.edu/cgboer/limbicsystem.html “The Emotional Nervous System” an explanation of the Limbic and Autonomic Nervous systems.

7. http://www.psych.nyu.edu/phelpslab/papers/interactions%20of%20the%20amygdala04.pdf “Human emotion and memory: interactions of the amygdala and hippocampal complex” a very interesting article on the formation of memory.

Appendix:

See the article “Remember This: In the Archives of the Brain, Our Lives Linger or Disappear” by Joshua Foer in November 2007 National Geographic Vol. 212, No. 5.Especially the diagrams on pages 42-43.