A good night’s sleep has long been recommended to those who have experienced a traumatic event but this could actually be the wrong advice, according to Oxford University researchers.
Their study showed sleep deprivation prevented the consolidation of memories of experimental trauma, therefore, reducing the tendency to experience flashbacks.
“Finding out more how sleep and trauma interact means we can ensure people are well cared for after a traumatic event”
Dr Kate Porcheret, from Oxford’s Nuffield Department of Clinical Neurosciences, said: “We wanted to see what effect sleep deprivation would have on the development of intrusive memories – what in a clinical setting are called flashbacks.”
The study, published in the journal Sleep, involved around 40 people, who were split into two groups.
“After showing participants a film of scenes with traumatic content, as an analogue to trauma, they were either kept in a sleep laboratory and deprived of sleep or sent home to have a normal night’s sleep in their own bed,” said Dr Porcheret.
Each person then kept a diary in which they recorded any intrusive memories, however fleeting, recording as much information as possible so that the research team could check that the intrusive images were linked to the film.
The sleep-deprived group was found to have experienced fewer intrusive memories than those who had been able to sleep normally.
Both groups experienced more of these involuntary memories in the first two days and a reducing number in the following days. We know that sleep improves memory performance including emotional memory, but there may be a time when remembering in this way is unhelpful.’
The study team stressed that further research was needed as there is currently limited understanding of intrusive memories of emotional events as well as of the role of sleep in responding to real trauma.
They also cautioned that real-life trauma could not be directly replicated in a laboratory study, such as theirs.
Dr Porcheret added: “Finding out more how sleep and trauma interact means we can ensure people are well cared for after a traumatic event. These are really important research questions to pursue further.
“For example, it is still common for patients to receive sedatives after a traumatic event to help them sleep, even though we already know that for some very traumatised people this may be the wrong approach,” she said.
“That is why we need more research in both experimental and clinical settings into how our response to psychological trauma is affected by sleep – and lack of sleep too,” she added.