Sleep deprivation eliminates fear generalization

January, 2011

In a small study, a sleepless night after trauma prevents the development of PTSD symptoms.

Given all the research showing the importance of sleep for consolidating memories, it should come as no great surprise that the reverse is also true: depriving yourself of sleep could help you forget experiences you would prefer not to remember.

In the study, 28 student volunteers were shown 14 short video clips, half of which showed safe driving down a city street, and half showed the car being involved in a nasty crash. Half of the volunteers were then deprived of sleep while the other half received a normal night's sleep. The next day, they were shown pictures and asked to indicate whether they had appeared in the clips they had seen. They were also asked to rate the fear evoked by the image, and their physiological responses measured. They were tested again 3 and 10 days later.

While there was no difference between the two groups in picture recognition, the control group rated the images from the crash videos as fearful, and these responses generalized over time to the other images. However, those who were sleep deprived showed such reactions only on the first day.

The finding suggests a possible therapy for PTSD or other anxiety disorders.

Reference:

[2051] Kuriyama, K., Soshi T., & Kim Y.
(2010). Sleep Deprivation Facilitates Extinction of Implicit Fear Generalization and Physiological Response to Fear.
Biological Psychiatry. 68(11), 991 - 998.

Source:

http://www.eurekalert.org/pub_releases/2010-12/e-lns120710.php
http://www.guardian.co.uk/science/blog/2010/dec/17/sleep-post-traumatic-...

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PTSD

Drug prevents post-traumatic stress syndrome

January, 2011

A new drug is successful in preventing PTSD in mice if delivered within 5 hours of the trauma.

A mouse study has revealed the brain becomes overly stimulated after a traumatic event causes an ongoing, frenzied interaction between two brain proteins long after they should have disengaged. However, the injection of newly developed drugs into the hippocampus within a five hour window calmed this process, and prevented the development of a post-traumatic fear response.

The new research shows the potential for PTSD occurs when a stressful event causes a flood of glutamate, which then interacts with a second protein (Homer1a). This protein continues to stimulate metabotropic glutamate receptor 5 [mGluR5] after the glutamate has dissipated. The new drugs bind mGluR5 and reverse its activity.