Propranolol, a beta-blocker drug developed in the 1960s, has been used to treat high blood pressure, chest pain and arrhythmias for decades. Recently, researchers at the University of Amsterdam have reinforced another use for the drug – curing phobias. Once patients took propranolol, they were able to touch a large, furry tarantula without the overwhelming physical response they had felt before. They even wanted to touch the spider repeatedly out of surprise that they could do it. Propranolol seems to work to treat phobias based on its interference with memory reconsolidation.
Memory Reconsolidation
In the past, people thought that memories had to be erased or prevented from being consolidated in the first place in order to block or eliminate the emotional response or irrational fears that memories can provoke. Memory consolidation is a process that occurs in the brain over time as a memory is created and reinforced. Every time the memory is revisited, it grows stronger. The first few hours after a memory is created are critical to the stabilization and storage of the memory. Recalling a memory involves the activation of certain neuronal pathways in the brain and the consequent biochemical or emotional response. Recalling traumatic memories usually conjures up the same emotional response that occurred during and after the memory was created, such as fear and anxiety.
Memory reconsolidation is the theory that a recalled memory can be changed. Each time a memory is recalled, it must be removed from storage, so to speak. If that memory is modified when it is recalled, it is returned to storage in its modified state. This could be why memories involving break-ups or losing loved ones become less painful over time. The emotional response to the memory becomes weaker, or the memory is incorporated with other events or feelings and is stored as such.
Erasing Fear from Memory
Because the different aspects of a single memory are stored in different parts of the brain, memory erasure would be extremely complex. Furthermore, most people wouldn’t want to completely lose all the knowledge stored in memories. Rather than trying to erase memories completely, new research is aimed at separating the content of the memory from the intense emotional response that follows. That way, patients could still retain the information they learned and re-utilize it without the same pain and suffering.
Over the years, researchers have tested propranolol for the treatment of phobias and PTSD on the basis of memory reconsolidation. In a study that was a collaborative effort between Doctors Pitman and Orr of Harvard Medical School and Doctor Karim Nader of McGill University, PTSD patients were treated with propranolol when they recalled traumatic memories. Propranolol blocks the synthesis of proteins that are necessary to consolidate and reconsolidate memories. Eventually, the patients were able to think about and do things that would normally provoke the intense emotional response of the memories without feeling the fear and anxiety. The study was published in Nature in 2009.
Merel Kindt of the University of Amsterdam was inspired by Nader’s early research and tried to do the same with propranolol and patients with phobias. Along with colleagues she conducted a study that involved 45 people with a fear of spiders. All patients were all followed up with throughout the year after the test. Every person in the study who hadn’t received a placebo had shown a lasting decreased fear of spiders, and their reactions of fear and avoidance had decreased. This study was published in the journal Biological Psychiatry in 2015.
A Great Leap Forward for Psychotherapy
Not erasing memory but separating it from the intense emotional response is a godsend for people with PTSD, phobias and even addiction. The ability to rapidly treat these fears and anxieties with medication and see a lasting response is a breakthrough for psychotherapy. More research needs to be conducted to move forward, but this could change the future of psychotherapy. Psychotherapy is a field where treatments have historically been unreliable, and these studies could lead to a proven and consistent approach to the treatment of PTSD and other phobias for the first time.
