Monday, December 26, 2011

Ethics of Memory-Altering Drugs

Disturbances in memory represent some of the most frightening aspects of several psychiatric and neurological diseases. It gets right to our sense of self as in many ways our memories shape our view of the world and are critical for our ability to function normally in it. We are often surprised, though, to find just how fallible our memories can be, especially for highly stimulating or traumatic events. Kubie took a particularly cynical view of the matter in a 1959 comment suggesting that humans have trouble telling the truth even when they try.[i]

There is little doubt that our memories are inherently subjective and are affected by myriad factors. Why, then, are so many worried about the potential implications of memory altering drugs? Is it because we recognize how susceptible our memories are to producing errors and do not want to push it further from reality, or, is it rather that we hold our memories as real records of truth and thus something that should not be manipulated even if we could? Most likely it is the latter. Unfortunately, exposure to trauma can lead to consolidation of painful memories with intense emotional attachments which can be effectively paralyzing. These types of memories serve no productive purpose.

This is a serious matter, as post-traumatic stress disorder (PTSD) is increasingly recognized as a major public health burden. Evidence suggests that up to 35% of witnesses to a traumatic event will develop PTSD at some point.[ii],[iii] So what is happening in the other 65% who experienced the same thing? This may be a good example of how memory is truly subjective and the emotional aspect – which may be most important in pathological memory problems such as in PTSD – can be dependent on the individual. In fact, recent studies using propranolol (a β-adrenergic receptor antagonist currently approved for hypertension) have shown that the emotional aspects can be dissociated from traumatic memories.[iv] A small cohort studied in 2003 suggested that propranolol may be able to prevent PTSD if given immediately after a traumatic event.[v] These results, while far from conclusive, suggest that it may be possible to dampen the painful, emotional part of memories without impairing an individual’s recollection of an event. In a way, that may lead to a more dependable account of an event without the subjective emotional coloring.

Immediate treatment after trauma to prevent painful memories is not an ideal way to fend off PTSD; especially since the majority of witnesses will probably not develop the condition. Hopefully, further research will lead to more targeted strategies that can treat PTSD at the first sign, perhaps in combination with talk therapy. In the mean time, propranolol and other drugs like it should be further studied and used as warranted if it becomes clear that they significantly reduce incidence of PTSD. For some, altering memory represents crossing a line that could set a precedent for more devious drug uses. In this case, that is not an immediate concern. Our memories have already been shown to be quite fallible and prone to errors. In some cases those errors can take a real psychological toll and if it is in our power to prevent them then we should do so.

--Ryan Purcell
Neuroscience Graduate Program 


Want to cite this post?
Purcell, R. (2011). Ethics of Memory-Altering Drugs. The Neuroethics Blog. Retrieved on , from http://www.theneuroethicsblog.com/2011/12/ethics-of-memory-altering-drugs.html


References  
[i] Kubie, Lawrence S. Implications for Legal Procedure of the Fallibility of Human Memory, 108 U. Pa. L. Rev. 59 (1959-1960)
[ii] Yehuda, Rachel. Post-traumatic stress disorder, New England Journal of Medicine, 2002; 346: 108-114
[iii] Kessler RC, Sonnega A, Bromet E, Hughes M, Nelson CB. Posttraumatic stress disorder in the National Comorbidity Survey. Archives of General Psychiatry 1995; 52: 1048-60
[iv] Kindt M, Soeter M, Vervliet B. Beyond Extinction: erasing human fear responses and preventing the return of fear. Nature Neuroscience 2008; 12: 256-8
[v] Vaiva G, Ducrocq F, Jezequel K, Averland B, Lestavel P, Brunet A, Marmar CR. Immediate treatment with propanolol decreases posttraumatic stress disorder two months after trauma. Biological Psychiatry, 2003; 54(9):947-9

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