How a good night’s sleep may help us restrict bad memories
ISLAMABAD: Our brains possess a natural mechanism to limit intrusive memories, which plays a vital role in preserving mental well-being.
However, a recent study conducted by researchers from the University of York and the University of East Anglia in the UK suggests that sleep disturbances and lack of sleep can impair this ability, leading to more persistent intrusive memories. This may contribute to various mental health issues, including anxiety, depression, and post-traumatic stress disorder (PTSD).
The research also highlights the importance of rapid-eye movement (REM) sleep, the phase where dreaming occurs, as it appears to be essential for the brain’s “housekeeping” process, helping to suppress unwanted memories and thoughts.Brain health, sleep, diet: 3 health resolutions for 2025
It is becoming increasingly clear that sleep plays a critical role in supporting overall health, particularly brain health and mental well-being.
This new study, published in the journal PNAS, delves deeper into the fascinating connection between sleep, brain function, and mental health.
The findings reveal that disrupted sleep compromises the brain’s ability to control intrusive memories, which could potentially lead to mental health conditions such as anxiety, depression, and PTSD.
Dr. Marcus Harrington, a lecturer in psychology at the University of East Anglia and a specialist in sleep, memory, emotion, and mental health, explained to Medical News Today that the study was inspired by the desire to better understand why some individuals struggle more than others to recover from traumatic experiences.
He told us:
“Almost everyone encounters a traumatic experience at some point in their lives, but only a small percentage develop post-traumatic stress disorder (PTSD). Why do some people recover from trauma effectively, while others are left grappling with severe symptoms? Addressing this complex question is a key focus in clinical psychology. One known factor that increases the likelihood of PTSD after trauma is poor sleep. However, the precise link between sleep deprivation and vulnerability to PTSD and other mental health conditions remains unclear.”
Sleep deprivation hinders the brain’s ability to suppress negative memories
In this study, researchers worked with 85 healthy adults aged 18–30 years, including 30 men and 55 women, who participated in an overnight sleep study at a laboratory. Roughly half of the participants (43 individuals) were kept awake all night, while the others enjoyed a full night of restful sleep.
To explore the impact of sleep on the brain’s ability to suppress unwanted memories and thoughts, the participants were first given an exercise. They viewed images of faces, some paired with negative scenes such as car accidents.
The following day, participants were asked either to recall or suppress the memory of the negative scenes associated with specific faces. During these tasks, researchers used functional magnetic resonance imaging (fMRI) to observe brain activity.
Results revealed that participants who stayed awake all night exhibited reduced activation in the right dorsolateral prefrontal cortex, a brain region involved in emotional regulation and inhibiting intrusive thoughts. In contrast, well-rested participants displayed increased activity in this area, along with decreased activity in the hippocampus, which is associated with memory recall.
The findings suggest that well-rested individuals were more effective at suppressing unwanted memories, a cognitive function termed “memory suppression.” Conversely, sleep-deprived participants showed impaired ability in this regard.
The researchers indicated that this impaired ability to suppress intrusive memories — and possibly other intrusive thoughts — could have significant implications for mental health, particularly in conditions like anxiety, depression, and PTSD.
Dr. Harrington elaborated, “We’ve long known that sleep deprivation impairs external behavioral control, such as inhibiting physical actions like pressing a button. This study confirms that it also affects our ability to regulate internal processes, such as controlling intrusive memories.”
However, he emphasized that understanding how sleep deprivation impacts the experience of suppressing unwanted memories is only part of the challenge. “We were equally interested in uncovering what happens inside the brain when individuals attempt to suppress memories after sleep loss,” Harrington explained.
“For this reason, we used functional MRI to capture images of participants’ brain activity during memory suppression. The insights provided by neuroimaging allow us to construct a more comprehensive picture of how sleep deprivation may contribute to mental health issues,” he added.
Commenting on the study results, Caroline Horton, PhD, professor of sleep and cognition at Bishop Grosseteste University in Lincoln, U.K., who was not involved in this research, told MNT:
