Memory editing for mental health – Part 3: Treating and preventing mental illness
Deep dive by Conor D’Andrade
Even with millions of years of evolution on its side, the human brain can still be duped from time to time. One area that can be particularly affected is in the creation and management of memories which is central to many cases of mental health issues, from post-traumatic stress disorder to substance abuse. In the third and final article on the subject, Conor D’Andrade discusses some of the key areas of psychology that our knowledge of memory reconsolidation is changing how we approach mental health.
By now, I’ve run you through how memories are formed and how we can manipulate that process for our benefit, hopefully in a way that genuinely makes sense (because I know this is a complicated topic!) Now we bring together all of what we’ve learned in parts 1 and 2 and examine some of the areas of mental health in which our knowledge of memory reconsolidation can really make a difference.
One major area that reconsolidation can be applied to is substance addiction rehabilitation. For some, cravings are a significant cause of relapse when trying to end a substance addiction, prolonging or even preventing their recovery. This is a major risk for their health, as long-term substance use, whether legal or illegal, will cause significant physical and psychological harm.
In people recovering from addiction, specific situations and cues can reactivate memories of substance use and cause a strong desire to use that substance again, even if the person truly feels they don’t want to. Wouldn’t it be useful if we could target these memories and update them…
This theory was tested in 2012 on people with an addiction to heroin. On day 1 of the experiment, cravings were measured for all participants. On day 2, they were split into three groups:
One group watched a neutral video followed by extinction treatment 10 minutes later
One group watched a video reminding them of substance abuse followed by extinction treatment 10 minutes later
One group watched a video reminding them of substance abuse followed by extinction treatment 6 hours later
Cravings were then measured on day 4, day 34, and day 184 since the beginning of the experiment.
As you may remember from part 2, using extinction treatment 10 minutes after a reminder of a stimulus (in that case, a sound associated with an electric shock) was particularly effective in removing all signs of fear. If you do remember that then you’ve probably spotted that group 2 is the group to look out for.
And you’d be right – even though extinction treatment reduced cravings for all groups, cravings for group 2 remained lower on days 4, 34 and 184 than they were on day 1. In comparison, the other two groups saw their levels of cravings gradually return to day 1 levels.
The reason why group 2 was such a success was that the extinction treatment had occurred during the reconsolidation process window which, in this instance, had been activated by the memory of substance abuse. The extinction treatment had essentially rewired the memory to remove the craving. As you can imagine, this is a huge weapon to have in the fight against substance abuse relapse.
Another mental health issue for which our knowledge of the reconsolidation process could help is in post-traumatic stress disorder (PTSD).
A common and core symptom of PTSD is intrusive memories which are memories that are experienced involuntarily, often as flashbacks, nightmares, or images. These can be incredibly debilitating as the individual is often unaware they are from the past, experiencing physical and emotional reactions to them as if they are a present threat.
In 2015, researchers attempted to treat PTSD by interrupting the reconsolidation of intrusive memories using a visuospatial task (top marks if you can remember what that is – if not, I explain what it is in part two). Interestingly, an unexpected star among visuospatial tasks has revealed itself as a top contender for interrupting the reconsolidation process… and that star is Tetris. And that’s exactly what the researchers used in their study.
On the first day of the study, all participants watched a traumatic film before recording any intrusive memories in a diary. The next day, they were split into four groups:
Group 1 were given no task and no extinction treatment
Group 2 were given a reminder of the film, given Tetris to play, and then given extinction treatment 10 minutes later
Group 3 were given Tetris to play and then extinction treatment
Group 4 were given a reminder of the film and no extinction treatment
On day 7, participants handed in their diaries and then asked to complete an ‘intrusion-provocation task’. As its name suggests, this task was designed to induce intrusive memories and consisted of participants being shown 11 blurred images from the traumatic video they were shown at the start of the study.
Which group do you think saw the biggest reduction in intrusive memories?
If you guessed group 2… then you’re absolutely right! The combination of a reconsolidation trigger, a visuospatial task of Tetris, and extinction treatment within the reconsolidation window resulted in significantly lower levels of intrusive thoughts compared with all other groups.
What if we could stop PTSD developing in the first place?
Being able to treat a symptom as distressing as intrusive memories, by interrupting their reconsolidation, is an exciting prospect for both individuals with PTSD and doctors. But this application of reconsolidation could potentially go a step further.
Research is beginning to focus on whether we can stop the formation of intrusive memories at all by interrupting the consolidation of the traumatic event that will cause them in the first place – essentially acting as kind of ‘cognitive vaccine’ that reduces the chances of developing PTSD altogether.
A study from 2017 tested this theory on people who had been admitted to an emergency department just after experiencing a traumatic motor accident. Participants were assigned to one of two groups: one was given a reminder of the event followed by Tetris; the other was given a reminder followed by a control task. Both groups were then given a diary to record any intrusive memories for the next 7 days.
And here’s what the results looked like:
The impact of Tetris on the average number of intrusive memories experienced. Source: Iyadurai et al 2018.
As you can see, playing Tetris after the reminder of the event caused a significant decrease in the number of intrusive memories participants experienced – reducing the number of intrusive memories experienced by participants by over half.
Combined with the fact that the participants in this study had actually experienced a traumatic event – making the results even more applicable to real life – while Tetris itself would be a very simple and cheap measure to implement, this study uncovered one of the most exciting developments in recent psychology.
Memory reconsolidation and the future of mental health
As I hope I’ve demonstrated throughout this series, memory reconsolidation and its uses are a fascinatingly complex, yet incredibly exciting, topic of psychology.
What’s perhaps most exciting is that our understanding of how we can best use this knowledge is still in its infancy, leaving plenty more to discover about how it can help with mental health. So, if this series has inspired you as much as it did me in my second year at university, spread the word about memory reconsolidation and give it the spotlight it deserves.