Certain anxiety disorders, such as obsessive compulsive disorder (OCD) and specific phobias, are often treated with exposure therapy, in which the patient is gradually exposed to the object or context that provokes the anxiety reaction. If exposure therapy is successful, a new “safe” memory is formed, which overshadows the old fear memory.
But some patients don’t experience success with exposure therapy, in part because the old fear memory may return at some later point even after an initially successful exposure. In addition, older and stronger memories have proven to be difficult to disrupt.
In a new study, researchers at Uppsala University and Karolinska Institutet in Sweden have now demonstrated that the improvements gained by exposure therapy can be made to last longer, and they show for the first time that it is possible to use this method to reduce fear in life-long phobias. They accomplished this by disrupting the recreation of fear-memories in anxiety patients by exposing them to a short-lived exposure before a longer exposure.
For the study, the researchers exposed individuals with arachnophobia (morbid fear of spiders) to spider pictures while measuring their brain activity in the amygdala, a part of the brain that is strongly linked to fear. They found that when they activated a fear memory for only a short amount of time — in this case, only 10 minutes — before engaging in a more extensive exposure, it led to significantly reduced amygdala activity when the subjects looked at the spider pictures again the following day.
In other words, the memory was made unstable and re-saved in its weakened form before the longer exposure. This made it so the fear could not return as easily.
The day after exposure, the group that received an initial activation of their spider fear showed reduced amygdala activity in comparison with a control group. Avoidance of spiders also decreased, which could be predicted from the degree of amygdala activation.
“It is striking that such a simple manipulation so clearly affects brain activity and behaviour. A simple modification of existing treatments could possibly improve effects. This would mean more people getting rid of their anxieties after treatment and fewer relapses,” says Johannes Björkstrand, Ph.D. student at the Department of Psychology, Uppsala University.
The findings are published in the journal Current Biology.
Source: Uppsala University