Islamabad-According to research, sleeping in the first 24 hours after a traumatic event may help people to process the memory more effectively and therefore minimize the symptoms of post-traumatic stress disorder.

Prof Birgit Kleim and colleagues from the University of Zurich and the Psychiatric University Hospital Zurich in Switzerland have carried out an experiment, the findings of which suggest that sleeping after a traumatic event can help to process the memories and help people to move on.

In the study, 65 female volunteers watched two videos - one neutral and one traumatic. After this, the group stayed in the laboratory for 24 hours. Half of the participants slept, while the others stayed awake. Those who slept had their sleep recorded by an electroencephalograph (EEG).

The participants then kept a journal recording their memories and any flashbacks over several days.

During this time, all the participants had intrusive memories. As the horrific scene they had viewed burst into their mind, it would stir up the negative feelings again.

However, those who slept after viewing the videos had fewer bad emotional memories and their recollections were less distressing than in those who stayed awake, especially toward the end of the week. The results suggest that sleeping after a distressing event might offer some protection from the effects of PTSD.

Readings from the EEG showed that the frequency of intrusions corresponded with the amount of time the person spent in stage N2 sleep, compared with light N1 sleep.

It was also reflected in a higher number of fast sleep spindles and a lower density of rapid eye movement (REM) sleep.

Non-REM sleep occurs in three stages: N1, N2, and N3.

N1 is the lightest stage and N3 is the deepest, also referred to as “deep” or “slow-wave” sleep. During the transition from N1 to N3, brain waves slow down and become more synchronized, and the eyes remain still.

In N3, an EEG will show large, slow waves and spindles.

Sleep is known to play a role in the processing of memories, including bad memories, and the authors hypothesize that it might impact traumatic memories in one of two ways.

It can either weaken the emotions that are linked to the memory, or it puts the memories into context, processes them, and stores them as information.

The team assumes that this process would take several nights.

Prof Birgit Kleim said, “Our approach offers an important non-invasive alternative to the current attempts to erase traumatic memories or treat them with medication. The use of sleep might prove to be a suitable and natural early prevention strategy.”

 The researchers point out that there are currently few early treatment options for people who are at risk of PTSD. They hope that sleep could be applied in this way to prevent the condition’s negative impact.