PTSD Memory Recall and Therapy

Posttraumatic Stress Disorder, or PTSD, can manifest in people who have experienced a significant traumatic event or events in their lives. PTSD patients can be affected by their trauma in either a physical, like drug use or a blow to the head, or emotionally, mental trauma. In 1980 PTSD was officially recognized as a psychiatric disorder that had its own set of symptoms, before this PTSD was recognized in war veterans as “shell shock”. The shell shock was identified when veterans came back from war with a change in personality, sudden intense mood swings, and bouts of violence. Exposure to the traumatic event can be either personal or through second hand encounters. Experiencing a traumatic event can have an effect on ones formations of memories for the event and future long term memories. PTSD symptoms can show up usually within 3 months after the event and can reside for 3 months to 3 years in a patient. Researchers have been looking into ways the brain manipulates memories to help treat patients with PTSD and ways to improve the life of patients with PTSD.

When a person experiences a traumatic event, they have an overactive recall of the event and often include details that in fact never happened. Traumatic experiences are not the only memories that have the capability to be distorted but when patients over experience their trauma they are more likely to exhibit symptoms of PTSD. Strange and Takarangi et al. 2015 studied the effect of source monitoring errors on traumatic experiences. Source monitoring error is one of the many ways memories can become distorted. When source monitoring error occurs, the brain is either unable to figure out whether a memory is from short term memory, long term memory, or even if the some of the memories being recalled are truly associated with the memory.

Strange and Takarangi et al. (2015) introduce two other studies that give alternative reasoning for this change in memory in patients. Crombag et al. (1996) shows the effect of outside media and resources affecting memory recall for a traumatic event. With just media coverage and priming by the researchers, participants elaborated and believed in the story they were given by the researchers. (Crombag et al. 1996) In this study it is shown that traumatic memories are more susceptible to change. A traumatic event affects a person in a way that gives them an avenue to emotionally manipulate their memories of the events.  In the second study they examined how participants recall personal trauma over time. Southwick et al. (1997) performed a longitudinal study on U.S. war veterans researchers saw that the greater the traumatic re-experiencing, or PTSD symptoms, the veterans experienced, the more likely they were to have a different recall of events. (Southwick et al. 1997)

Strange and Takarangi et al. (2015) claim to have found a third piece of evidence linking alterations in traumatic memories and how the mental imagery of these events affect recall. Participants were shown a video in a lab setting of a car crash with some clips removed and replaced with a white screen for seconds at a time. After viewing this video the participants were asked back the next day, when they sat down the participants were shown video clips, some of the original video they saw, some of the clips that had been replaced with blank screens, and finally completely new clips of a different video. When the participants recorded their answers they mostly identify the new clips successfully but were more likely to claim new and missing clips as old clips if they were more traumatic. After this initial test, Strange and Takarangi et al. (2015) conducted a follow up study to determine whether the participants were filling the gaps in the video intentionally with the missing clips they were shown or they did not notice the gaps missing and they unintentionally filled that gap. To test this, they showed participants two different versions of the video, one that emphasized the removal of clips while the other simply transitioned to the next clip without a gap. The results of this showed now difference between the conditions so the researchers added another condition, warning the participant that there would be or not be missing information. After testing the participants in this condition Strange and Takarangi et al. (2015) concluded that when participants were warned that there was information missing their recall was more accurate. When a written description was overlaid on the missing footage gap participants had less success recalling what was actually shown versus what was missing footage.

This  study by Strange and Takarangi et al. 2015 overall shows that 3rd party resources surrounding traumatic events had an effect on source monitoring errors. When a participant was given outside information about an event they were more likely to recall false information. Without outside information, traumatic events are still susceptible to recall error due to other factors.(Southwick et al. 1997, Crombag et al. 1996) Source monitoring errors are a major reason for information recall when it comes to witnessing traumatic events.

Lunius and Collegues et al. (2001) used neuroimaging with an fMRI to map a PTSD patients neural activity. These patients were not fully diagnosable by the DSM with PTSD but met the requirements for showing significant signs of trauma. These 9 patients were either victims of sexual assault or motor vehicle accidents. Some participants showed signs of concurrent mental illness including major depression, dysthymia, and panic disorder. Patients also admitted to drug and alcohol abuse. To increase internal validity the patients selected were all similar in age, gender, and race.

The method used by Linius and Colleagues et al. (2001) was having the patients exposed to a traumatic script and asked to recall all the moments of trauma. The script lasted 30 seconds then asked to recall for 60 seconds, they were then presented with the script 120 seconds after. Heart rate and increased blood flow in areas in the brain to represent increased activity. Using a one tailed t test the researchers were able to conclude there was a significant amount of activation in the comparison group to the PTSD group. (Linius and Colleagues et al. 2001) The study also showed that 60 seconds was enough time to recover from the script and carryover effect was not shown neurally. The heart rate baseline did increase in PTSD patients. (Linius and Colleagues et al. 2001)

The study by Linius and Colleagues et al. (2001) shows the memory dissociation patients with PTSD can encounter. Lower brain activity in the thalamic region, associated with emotions, presents researchers with new information that the traumatic experience they experience can dull the thalamic sensory processing. With this information PTSD patients can be better treated for their memory dissociation as well as memory flashbacks that some patients experience.

PTSD can be presented in many ways through patients but to be diagnosed with PTSD patients must exhibit symptoms for more than a month. In the study Holmer and Colleagues et al. (2014) researchers performed a case study on an eleven year old girl who had been exposed to the traumatic event of her mother going through cancer. The girl was referred to specialists once her behaviors changed and her grades began to drop drastically. In this study she was first assessed for PTSD regarding her symptoms. Once diagnosed, she underwent Cognitive Behavioral Therapy and the researchers reevaluated her after a year. Cognitive Behavioral Therapy includes a positive look on changing one’s behavior instead of recalling the negative events in one’s life, as many traditional therapies do. The child was taught relaxation techniques and how to desensitize her traumatic memories, her school and family was also taught techniques of how to handle her PTSD symptoms.

The results of this study were focused on the child’s rehabilitation and showed significant decreases in the Child Stress Scale. Not only did her scores on the scale decreased significantly but her social responses also improved in school and home life. This study shows that CBT is effective in treating symptoms for PTSD in children and can be referenced for future studies in adults.

PTSD can be treated effectively in many ways including, therapy, narrative exposure therapy, and a drug called propranolol. Propranolol is a beta blocker drug that is able to directly affect parts of the brain due to its ability to easily cross through the brain. Schwabe et al. (2012) researched the effects on the brain post memory reconsolidation therapy and propranolol. In this study healthy participants were used instead of participants with PTSD, as many PTSD focused studies do, this gives researchers a clearer understanding on how the drug affects the brain with controlled traumatic experiences instead of adding uncontrollable variable of naturally occurring PTSD. The participants were split into two seperate groups, one was shown basic photos while the other group was shown traumatically graphic photos. After viewing these images the patients were asked to recall the photo while under magnetic imaging to track the activity in their brain. While the experimental group was performing their recall propranolol being administered impaired the memory recall. Their study is mainly focused on the brain activity, they found that the amygdala and the hippocampus showed increased energy.

Schwabe et al. (2012) gives the explanation to this increase of activity as the brain needing to use more power to remember the disturbing images without the addition of the emotions that correspond with the memory. Though using a very controlled lab experiment to study the effects of propranolol is effective because it rules out a lot of third variables, true trauma and PTSD is not caused by merely a photograph set of disturbing images. This study does open up further research to understand the effects of propranolol upon recall of a traumatic or emotionally disturbing memory.

In the study Villain and Benkahoul et al. (2018) the effects of early stress on traumatic memories and the effects of reconsolidation therapy in conjunction with Propranolol were being researched. To make the study more specific and increase internal validity they studied the specific effect of pre and postnatal stress on a traumatic event. Mice were used in this study and they were exposed to a fear condition and then reintroduced to elements of the fear condition. After being exposed in a new environment they were administered propranolol to see the effects of the drug during reconsolidation. Half of the group was born from stressed mothers while the other half was not to test the effects of pre and postnatal stress. The stress conditions were 3 different stages, keeping the mice in a small enclosure, a swimming stress test, and an electric shock floor test. The traumatic event of the new mice occurred in a box that they had already been familiarized with. The trauma consisted of either shock, flashing lights, olfactory, high pitched sounds, or tactile stress through a copper plate. When in this condition they were administered a shock. At later dates the mice were exposed to a completely different stress, placed in a tight space similar to the pre and post natal stress conditions. To access the mice memories of the first trauma experiences, 5 days later they measure the reluctance to walk into the corners of the box that had shocked them. In addition to this long term study they held a 24 hour study of mice and their freezing time to a sound that had been followed by a shock the day before. (Villain and Benkahoul et al. 2018)

Villain and Benkahoul et al. (2018) found with a two way analysis of variance that propranolol was effective in blocking the reconsolidation of the traumatic condition but not the reconsolidation of the fear condition. In addition the propranolol showed no effect on early stress. With this information the idea of early stress making  propranolol ineffective in PTSD patients can be ruled out. Propranolol is shown to not block the beta system for fear conditions but the actual traumatic memory. This enables further research into PTSD, and the effectiveness of propranolol, treatment more specific.

The research presented shows that traumatic memories are not only susceptible to changes from outside sources but the symptoms presented due to PTSD can also be treated by therapy and the drug propranolol. All memories are susceptible to change over time but the effects of a third resource on personal and nonpartisan traumatic events. The changes can be caused by media coverage in nonpartisan events and in personal events we see time and memory recall manipulate the memories. We see the effects of recall  parts of the brain in trauma patients showed less activity to traumatic scripts than the control participants. (Lanius and Colleagues et al. 2001) The manipulation after recall can cause a person to feel they experienced a more traumatic event than they truly did. With the study by Holmer and Colleagues et al. 2014 it is shown that recalling a traumatic memory may not be as effective as recall therapy. In conjunction to that the studies by Villain and Benkahoul et al. (2018) and Schwabe et al. (2012) show that memory recall therapy can in fact be effective when the drug propranolol is administered during memory recall.

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