Unwanted thoughts are easier to control when rested

It’s not uncommon for unwelcome thoughts to cross a person’s mind now and again. 

According to psychologist Marcus Harrington of the Department of Psychology at the University of York in the United Kingdom, “For most people, thought intrusions pass quickly, but for those [who are experiencing] psychiatric conditions, such as post-traumatic stress disorder (PTSD), they can be repetitive, uncontrollable, and distressing.”

Harrington is the lead author of a new study investigating the effect of sleep deprivation on unwanted thoughts.

The study finds that sleep deprivation increases the frequency of unwanted thoughts and lessens an individual’s ability to control them.

Funded by the Medical Research Council, the research appears in Clinical Psychological Science.

Unwanted thoughts

“In everyday life,” says Harrington, “mundane encounters can remind us of unpleasant experiences. For example, a car driving too fast on the motorway might cause us to retrieve unwanted memories from a car accident many years ago.”

However, for people with some psychiatric disorders, unwelcome thoughts can be a frequent, persistent, and often emotionally destructive intrusion.

“It is clear,” says Harrington, “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.”

A lack of sleep and the resulting inability to manage unwelcome thoughts may also be self-perpetuating.

“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.”

– Senior author Dr. Scott Cairney