A recent study has shed light on the critical link between sleep and mental health, revealing that poor sleep can impair brain regions responsible for suppressing unwanted, intrusive memories. These memories can be a hallmark of mental disorders such as depression, anxiety, and post-traumatic stress disorder (PTSD).
Researchers at the University of East Anglia, UK, led by Dr Marcus Harrington, conducted a study involving 85 healthy adults. Participants underwent functional MRI brain scans while attempting to suppress unwanted memories, with half the group well-rested and the other half sleep-deprived.
The results showed that sleep-deprived individuals struggled to engage brain regions that normally suppress memory retrieval. In contrast, well-rested participants exhibited heightened activity in the right dorsolateral prefrontal cortex, a region responsible for controlling thoughts, actions, and emotions. This heightened activity was accompanied by reduced activity in the hippocampus, a region involved in memory retrieval.
Notably, the study found that REM (rapid eye movement) sleep, the stage when dreams occur, played a crucial role in restoring brain function related to memory control. Participants who spent more time in REM sleep were better at engaging the right dorsolateral prefrontal cortex during memory suppression.
The findings have significant implications for our understanding of the relationship between sleep and mental health. "Memories of unpleasant experiences can intrude into conscious awareness, often in response to reminders," Dr Harrington explained.
"Given that memories play a central role in our affective perception of the external world, memory control failures may go a long way towards explaining the relationship between sleep loss and emotional dysregulation," he added.
The study's results could also inform the development of treatments and prevention strategies for mental illnesses such as depression and anxiety. By highlighting the critical role of sleep in maintaining control over memories and ongoing thoughts, this research underscores the importance of prioritizing sleep for optimal mental health.
