If there are days you can’t seem to get bad thoughts out of your mind you may want to remember back to how well you slept the night before. That’s because researchers have discovered lack of sleep significantly affects your ability to stop unpleasant and unwanted thoughts from entering your mind.
The premise of the study conducted at England’s University of York was simple in nature. Researchers wanted to test the ability of study participants to suppress unwanted thoughts when they were either well rested or sleep deprived. The ones who were sleep deprived had an increase of nearly 50 percent in unwanted thoughts compared to those who were well rested.
Scientists believe the findings could have implications for people suffering PTSD, depression, schizophrenia and other conditions associated with unwanted thoughts.
“In everyday life, mundane encounters can remind us of unpleasant experiences,” said Dr. Marcus Harrington from the Department of Psychology at the University of York. “For example, a car driving too fast on the motorway might cause us to retrieve unwanted memories from a car accident many years ago. For most people, thought intrusions pass quickly, but for those suffering with psychiatric conditions such as post-traumatic stress disorder, they can be repetitive, uncontrollable, and distressing.”
Dr. Harrington went on to say, "It is clear that the ability to suppress unwanted thoughts varies dramatically between individuals, but until now the factors that drive this variability have been mysterious. Our study suggests sleep loss has a considerable impact on our ability to keep unwanted thoughts out of our minds."
The study involved 60 participants who were asked to associate faces with photographs of different scenes such as an image of war for a negative scene and an image of a cityscape for a neutral scene. After a night of either sleep or total sleep deprivation the participants were shown the faces again. They were then asked to suppress thoughts related to the scenes.
The sleep deprived participants had a much harder time keeping the unwanted thoughts of both the negative and neutral scenes out of their minds. The ones who had been getting good sleep found the exercise to be easier as time went on but the sleep deprived subjects found controlling their thoughts consistently hard.
Interestingly, the ones who slept well came to view the negative scenes more positively over time and had a reduced sweat response to those scenes. That was not the case with the sleep deprived.
"This study offers an important insight into the impact of sleep on mental health,” said Dr. Scott Cairney from the Department of Psychology at the University of York. "The study also suggests that the onset of intrusive thoughts and emotional disturbances following bouts of poor sleep could create a vicious cycle, whereby upsetting intrusions and emotional distress exacerbate sleep problems, inhibiting the sleep needed to support recovery."