Summary: Researchers report that exposure therapy for spider phobia can be made more durable by disrupting the reconsolidation of fear memories.
Source: Uppsala University.
Exposure therapy is a widely used treatment for anxiety and phobias. In a new study published in Current Biology, researchers at Uppsala University and Karolinska Institutet show that a brief activation of an existing fear memory just before exposure can weaken lifelong spider fears by interfering with the memory’s reconsolidation.
Up to 30 percent of people will experience an anxiety disorder at some point in life. Exposure therapy—gradually confronting the feared object or situation—is an effective treatment because it helps form a new, safer memory that suppresses the original fear. However, not all patients achieve lasting relief: the new learning is sometimes temporary and the original fear can return. The new study demonstrates a way to make the effects of exposure more persistent by targeting memory reconsolidation.
When a memory is recalled it becomes briefly labile and must be re-stored, a process called reconsolidation. If reconsolidation is disrupted, the re-stored memory can be altered or weakened. This mechanism has raised hope for more durable clinical interventions, but stronger, long-standing memories have been considered resistant to disruption. The present study tested whether reconsolidation disruption could modify natural, long-term fears in humans.
The investigators recruited individuals with lifelong arachnophobia and monitored brain activity in the amygdala, a region closely tied to fear processing, while participants viewed pictures of spiders. The experimental procedure involved a short reminder or activation of the fear memory followed, after a brief interval, by an extended exposure session. The critical comparison was between conditions in which exposure occurred during the reconsolidation window and conditions in which it did not.
Participants who received a short fear reminder followed by exposure ten minutes later showed significantly reduced amygdala activation when tested 24 hours after treatment, compared with participants whose exposure occurred outside the reconsolidation window. Behaviorally, those in the reconsolidation-disruption condition also showed reduced avoidance of spiders. Moreover, the degree of amygdala activation predicted approach behavior: lower amygdala responses were associated with greater willingness to approach feared cues.
“It is striking that such a simple manipulation can produce clear changes in both brain activity and behavior,” says Johannes Björkstrand, a PhD student at the Department of Psychology, Uppsala University. “A modest adjustment to existing exposure protocols—activating the memory just before training—could strengthen treatment durability, helping more people overcome anxiety with fewer relapses.”
Source: Johannes Björkstrand – Uppsala University
Image Source: This image is provided for illustrative purposes.
Original Research: Abstract for “Disrupting Reconsolidation Attenuates Long-Term Fear Memory in the Human Amygdala and Facilitates Approach Behavior” by Johannes Björkstrand, Thomas Agren, Fredrik Åhs, Andreas Frick, Elna-Marie Larsson, Olof Hjorth, Tomas Furmark, and Mats Fredrikson in Current Biology. Published online August 25, 2016. doi:10.1016/j.cub.2016.08.022
Uppsala University. “Memory Activation Before Exposure Reduces Life-Long Fear of Spiders.” NeuroscienceNews. 25 August 2016.
Abstract
Disrupting Reconsolidation Attenuates Long-Term Fear Memory in the Human Amygdala and Facilitates Approach Behavior
Highlights
• Memory activation prior to exposure training attenuates the expression of lifelong fears
• Disruption of reconsolidation decreases amygdala activity during fear provocation
• Disruption of reconsolidation increases approach behavior to feared cues
• Amygdala activity during fear provocation predicts approach behavior
Summary
Recall renders memories labile and open to modification. Experimental work in animals and humans has shown that brief disruption of reconsolidation—by administering extinction-like exposure shortly after memory activation—can reduce conditioned fear that is stored in the amygdala. Whether the same principle applies to naturally occurring, long-standing fears has been unclear because older memories can be more resistant to change. In this human imaging study of participants with a lifelong fear of spiders, fear memory activation followed by repeated exposure after a short delay (10 minutes) attenuated basolateral amygdala activity at re-exposure 24 hours later. By contrast, exposure presented outside the reconsolidation window (6 hours after activation) did not reduce amygdala responses. Only the disrupted reconsolidation condition produced increased approach behavior toward feared cues, and individual differences in amygdala activity during re-exposure predicted approach. These results indicate that brief memory activation immediately preceding exposure can weaken decades-old fear memories, implicating the basolateral amygdala in the neurobiological mechanism and suggesting a simple modification that could enhance clinical exposure therapy.
“Disrupting Reconsolidation Attenuates Long-Term Fear Memory in the Human Amygdala and Facilitates Approach Behavior” by Johannes Björkstrand et al. in Current Biology. Published online August 25, 2016. doi:10.1016/j.cub.2016.08.022