An article in October’s Biological Psychiatry reports that immediate sleep maintains emotional memories and suggests an intriguing hypothesis – that post-traumatic stress disorder could be prevented by stopping people from sleeping immediately after a traumatic event.
A research team, led by psychologist Ullrich Wagner, asked tired participants to learn neutral texts (such as a piece about dressmaking) or emotional texts (such as a piece about child murder).
Some of the participants slept immediately, others were kept awake for three hours after learning.
Four years later, the participants were tested for how well they had remembered the texts.
Those who had slept immediately after learning had better memory than those who hadn’t, but only for the emotional topics.
This suggests that sleep helps consolidate memory most effectively for emotional material.
The researchers argue that these results suggest a simple way of dampening the impact of intense memories that form one of the main features of post-traumatic distress disorder: intrusive vivid memories of the event.
“From a clinical perspective, our results suggest the use of sleep deprivation in the immediate aftermath of traumatic events as a possible therapeutic measure to prevent a long-term engravement of these events in memory, thereby at least partly counteracting the development of PTSD as a disease thought to reflect overconsolidated emotional memories.”
Although not widely known, sleep deprivation is not a new treatment for psychiatric disorders.
It is known that missing a night’s sleep can significantly improve mood, even in people with severe depression.
Unfortunately, the improvement is often lost when people catch up on their sleep and it is still not clear why these effects occur.
Link to abstract of ‘Brief sleep after learning keeps emotional memories alive for years’.
Link to abstract of ‘Therapeutic use of sleep deprivation in depression’.
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