From recreational mind-altering drugs to pharmaceuticals that target neurotransmitter imbalances, a wide variety of chemical mechanisms can alter our thought processes and behaviors. While neural bases have long been known to play a role in shaping our thoughts and actions, recent advances in memory research have brought an evocative question to the forefront: what if we could change not only how we think and act, but also what we remember? The concept of a “forgetfulness” drug—an Eternal Sunshine-esque memory erasure treatment in pill form—is no longer a far-fetched fantasy. As researchers formulate a better understanding of how memories are formed and retrieved at the molecular level, the scientific community gains the ability to formulate targeted approaches to modifying the existence or emotional character of past memories. However, amid these developments, it is crucial that scientists, neuroethicists, and policymakers collaborate to evaluate the ethical costs and benefits of new therapies.
Currently, a number of drugs have shown utility in altering memory consolidation and retrieval. For example, propranolol, a beta-adrenergic blocker already approved by the FDA to treat hypertension, inhibits excess stress hormones released at the time of a psychologically traumatic event, the presence of which influences the memory consolidation of particularly emotional experiences.1 When administered during this critical period shortly after trauma, propranolol has also been shown to prevent the formation of strong, intrusive memories of the event, as well as the associated fear and anxiety that contribute to the later development of posttraumatic stress disorder (PTSD). In fact, early studies from 2002 and 2003 have demonstrated that patients who received propranolol, first administered several hours after a traumatic event and continued over a seven- or ten-day regimen, experienced lower rates of PTSD than those who did not receive propranolol.5,8
Memory-attenuating drugs can also be administered during subsequent periods of memory activation. More recently, advances in neuroscience have revealed that the process of retrieving memories is vastly different from the idea of simply activating consolidated memory traces from an archive. Instead, every time we recall a particular memory, it becomes unstable and must be re-consolidated in order to persist in the brain.7 Accordingly, a 2012 study conducted by clinical psychologists at the University of Amsterdam used propranolol to disrupt the memory reconsolidation of events associated with fear and anxiety in a learning context. Specifically, participants were threatened with painful electric shocks during a learning task; then, these acquired memories and fear conditioning were reactivated the following day during a repeat of the task. As predicted, participants who received propranolol during the memory reconsolidation process (upon activation of their memories from the previous day) showed lessened behavioral expressions and feelings of anxiety concerning the fear-related memory.7 Furthermore, within the past year, researchers have demonstrated that the injection of ζ-pseudosubstrate inhibitory peptide (ZIP) can induce cocaine-addicted rats to forget the locations where they had been receiving cocaine.4 Therefore, beyond diminishing the negative emotional experience of unpleasant memories, pharmaceutical treatments may also work toward erasing a memory altogether.
However, the power to eradicate memories comes with great responsibility—and a range of complex ethical implications. A decade ago, the President’s Council on Bioethics issued a report warning against the pharmaceutical modification of memories, citing various personal and social repercussions incurred by the use of any drugs that quell recollection of past events, regardless of how painful they may be.6 At the personal level, individuals might use such drugs to “numb” themselves from remembering incidents that could later prove to have adaptive value, thus obviating the process of learning and growing from negative experiences. On the greater social scale, some neuroethicists argue that if survivors and witnesses of catastrophic events (such as accidents, crimes, combat, or genocide) elect to eliminate the emotional charge of such memories, then their firsthand perceptions about the meaning and impact of these events—which are inevitably interlinked with powerful aversive emotions—would be altered substantially. In effect, these self-protective acts of deliberate forgetfulness would render emotionally devastating atrocities as less significant in the collective sense of justice and moral consciousness of society.6
On the other hand, not every negative memory has “redeeming” value. For example, individuals with PTSD experience recurrent traumatic memories that remain particularly vivid and emotionally distressing long after the event, often impeding day-to-day functioning. Accordingly, biomedical ethicists have likened the suffering resulting from agonizing memories to the experience of profound physical pain, the pharmaceutical alleviation of which is already a common, morally-accepted practice.2
Furthermore, a recent neuroethics editorial in Nature argued that fear surrounding the widespread abuse of pharmaceutical memory erasure is overblown and impedes the development of therapeutic applications to patients whose quality of life is curtailed by the residual effects of past traumatic experiences.3 After all, conscientious negotiation of legal policies and clinical guidelines for such drugs would reduce the possibility of large-scale abuse. From the drug administration perspective, clinicians and potential patients could work together to draft procedures for determining the types of cases in which the prescription of memory-dampening drugs is a viable option. Open communication between biomedical and legal experts would also be crucial in navigating high-stakes situations, such as when a traumatized sole witness to a violent crime seeks pharmaceutical memory erasure during an ongoing court case.
Ultimately, the ethical implications of erasing memories pose core questions surrounding our identity and humanity. Would electing to forget past events fundamentally change people—with the disappearance of certain salient memories potentially eroding away the basis of our individual perspectives and learning experiences? Or is simply forgetting a senselessly traumatic event sometimes the better option toward living a fully productive life? Although research on memory-erasing drugs is ongoing and the associated ethical issues of their implementation remain points of contention, the essence of the question lies at the individual level: if presented with the option, would you be willing to dull the emotional overtones of a personal memory, or erase that memory altogether?
- Cahill, L., et al. Nature. 1994, 371, 702-704.
- Illes, J. Am. J. Bioethics. 2007, 7(9), 1-2.
- Kolber, A. J. Nature. 2011, 476, 275-276.
- Li, Y-Q., et al. J. Neurosci. 2011, 31, 5436-5446.
- Pitman, R. K., et al. Biol. Psychiatry. 2002, 51, 189-192.
- President’s Council on Bioethics. Beyond Therapy: Biotechnology and the Pursuit of Human Happiness. 2003, 205-273.
- Soeter, M., & Kindt, M. Psychoneuroendocrinology. 2012, 37, 1769-1779.
- Vaiva, G., et al. Biol. Psychiatry. 2003, 54, 947-949.