Sleeping after a traumatic event can make memories, flashbacks worse

An Oxford University research has found that sleeping after a traumatic event or going to bed angry could make bad memories and flashbacks worse.

They showed 42 people disturbing video images of people suffering and then allowed half to go home and sleep as normal while the rest were kept awake in a laboratory.

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.

They found that the sleep-deprived group experienced around 40% fewer intrusive memories than those who had been able to sleep normally.

According to Dr Katharina Wulff, from the Sleep and Circadian Neuroscience Institute:

“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 team however say further research is 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, and that real-life trauma cannot be directly replicated in an laboratory study.

Dr Kate Porcheret from Oxford’s Nuffield Department of Clinical Neurosciences said ''finding out more how sleep and trauma interact means we can ensure people are well cared for after a traumatic event."