This previously unanswered question was addressed in a recent University of Zurich study.
Investigators discovered sleep, especially during the first 24 hours after a trauma, appears to play a key role in helping individuals manage the stress and emotional impact related to the event.
Experts say the knowledge is highly relevant for the prevention of trauma-related disorders, such as post-traumatic stress disorder (PTSD).
The way in which extremely distressing experiences are processed right at the outset can influence the further course and development of post-traumatic stress disorders.
PTSD patients experience highly emotional and distressing memories or even flashbacks where they feel as if they are experiencing their trauma all over again. Sleep could play a key role in processing what they have suffered.
In the new study conducted by a team from the Department of Psychology at the University of Zurich, researchers sought to determine the impact of sleep during the first 24 hours after a trauma.
To do this, investigators showed test subjects a traumatic video. The recurring memories of the images in the film that haunted the test subjects for a few days were recorded in detail in a diary.
Virtually out of the blue, the test subjects would see a snapshot of what they had seen in their mind’s eye, reawakening the unpleasant feelings and thoughts they had experienced during the film.
The quality of these memories resembles those of patients suffering from post-traumatic stress disorders. Other than after a traumatic event, however, they reliably disappear after a few days.
Investigators randomly assigned study participants to two groups. One slept in the lab for a night after the video while their sleep was recorded via an electroencephalograph (EEG); the other group remained awake.
“Our results reveal that people who slept after the film had fewer and less distressing recurring emotional memories than those who were awake,” explains first author Birgit Kleim.
“This supports the assumption that sleep may have a protective effect in the aftermath of traumatic experiences.”
On the one hand, sleep can help weaken emotions connected to an existing memory, such as fear caused by traumatic experiences, for instance.
Sleep also helps contextualize the recollections, process them informationally and store these memories. However, this process presumably takes several nights.
According to the authors of the study, recommendations on early treatments and dealing with traumatized people in the early phase are few and far between.
“Our approach offers an important non-invasive alternative to the current attempts to erase traumatic memories or treat them with medication,” says Birgit Kleim.
“The use of sleep might prove to be a suitable and natural early prevention strategy.”
Source: University of Zurich