Depriving people of sleep after a traumatic event may be the key to preventing the memory from plaguing them in the future. Post-traumatic stress disorder (PTSD) affects people who have been through severe traumas, like veterans, and can significantly disrupt their lives for decades after the initial event.
People who experience traumas often experience insomnia afterwards, which may be the body’s way of naturally trying to diminish the 'fear-magnifying effects of memory.'
Recently, much research has looked into how sleep helps memories form — a phenomenon called memory consolidation — and how disrupting sleep actually seems to disrupt the formation of memory. The current study expanded on this idea by depriving people of sleep to see if the formation of fear-based memories could be interrupted before they became "wired" in the brain.
The researchers had 14 healthy participants watch videos of safe, uneventful driving as well as clips in which upsetting car accidents occurred. After watching these clips, half the participants were allowed to get a normal night’s sleep and the other half were deprived of sleep for the entire night. The participants’ generalized fear response (their rating of their own fear) and physiological fear responses (based on a test called the skin conductance response) were tested three and 10 days after watching the video clips.
The researchers are hopeful that the phenomenon shown in the study may be used to treat people who might otherwise develop PTSD after a traumatic event. They point out that people who experience traumas often experience insomnia afterwards, which may be the body’s way of naturally trying to diminish the "fear-magnifying effects of memory."
In the journal’s press release, study author Kenichi Kuriyama says that "[s]leep deprivation after exposure to a traumatic event, whether intentional or not, may help prevent PTSD. Our findings may help to clarify the functional role of acute insomnia and to develop a prophylactic strategy of sleep restriction for prevention of PTSD."
Just how this research will drive PTSD treatments in still unclear since it might be difficult, in practice, to deprive trauma victims of sleep at the appropriate time while still allowing them to get the necessary benefits of sleep. Journal editor John Krystal suggest that, in the future, effective medications may be developed to solve the problem: "New insights into the neurobiology of sleep dependent learning may make it possible for these people to take a medication that disrupts this process while leaving restorative elements of sleep intact."
The study was carried out by researchers at the National Institute of Mental Health in Tokyo, Japan, and published in the December 1, 2010 issue of Biological Psychiatry.
