Loss of Sleep Raises Risks for Anxiety and PTSD

By Jim Windell

This new study appears in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. Entitled “Partial and Total Sleep Deprivation Interferes with Neural Correlates of Consolidation of Fear Extinction Memory,” the study provides us with new insights into how sleep deprivation affects brain function to disrupt fear extinction.

            The researchers, led by Anne Germain, PhD, at the University of Pittsburgh, and Edward Pace-Schott, PhD, at Harvard Medical School and Massachusetts General Hospital, studied 150 healthy adults in the sleep laboratory. One third of subjects got normal sleep, one third were sleep restricted, so they slept only the first half of the night, and one third were sleep deprived, so they got no sleep at all. In the morning, all the subjects underwent fear conditioning.

           In the conditioning paradigm, subjects were presented with three colors, two of which were paired with a mild electric shock. Following this fear conditioning, the subjects underwent fear extinction, in which one of the colors was presented without any shocks to learn that it was now "safe." That evening, subjects were tested for their reactivity to the three colors, a measure of their fear extinction recall, or how well they had "unlearned" the threat. The researchers used brain imaging recorded during the tasks. This brain imaging showed activation in brain areas associated with emotional regulation, such as the prefrontal cortex, in people who got normal sleep.

           But the brain activity looked very different in people with restricted sleep, said Dr. Pace-Schott. "We found that among the three groups, those who had only gotten half a night's sleep showed the most activity in brain regions associated with fear and the least activity in areas associated with control of emotion," Pace-Schott said.

           Interestingly, people who got no sleep lacked the brain activation in fear-related areas during fear conditioning and extinction. And during the extinction recall 12 hours later, their brain activity looked more similar to those with normal sleep, suggesting that a limited night of sleep may be worse than none at all. The researchers hypothesize that sleeping only half the night results in a loss of rapid eye movement (REM) sleep, which has been shown to be important for memory consolidation and usually happens toward the end of a normal sleep period.

           "Medical workers and soldiers often have curtailed or interrupted sleep rather than missing an entire night's sleep," Pace-Schott said. He went on to say that their findings suggest that such partially sleep-deprived individuals might be especially vulnerable to fear-related conditions such as posttraumatic stress disorder.

           To read the original journal article, find it with this reference:

           Jeehye Seo, Edward F. Pace-Schott, Mohammed R. Milad, Huijin Song, & Anne Germain. Partial and Total Sleep Deprivation Interferes with Neural Correlates of Consolidation of Fear Extinction Memory. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 2020; DOI: 10.1016/j.bpsc.2020.09.013