Scientific American Mind Article

In his article, “Can a Lack of Sleep Cause Psychiatric Disorders?”, Nikhil Swaminathan discusses the biopsychological implications of sleep deprivation. He describes a study conducted by Dr. Matthew Walker, a psychologist from the University of California, in which the brain activity of well-rested and sleep-deprived adults were monitored as they were shown a series of images that became progressively more disturbing. Primarily focusing on activity in the amygdala—the region of the brain that is responsible for emotional response—the investigators found that neurons in the sleep-deprived participants exhibited 60% increase in neuronal response due to transmission of impulses by five times as many than those of their well-rested contemporaries. Further investigation through fMRI analyses discovered than norepinephrine was being secreted by the activated neurons, thereby causing a fight-or-flight response.

Physiologically, the latter findings inhibit the activity of the medial prefrontal cortex, the region of the brain that regulates emotional responses and allows rational thought. This occurs as a result of sleep deprivation, and, thereby, accounts for the constant shift in moods within an individual. Harvard Medical School professor, Robert Stickgold, states that a relationship exists between sleep deprivation and certain psychiatric disorders, such as depression. Further studies will examine disturbances in different types of sleep, such as REM or slow-wave sleep.

I found this article particularly intriguing because, throughout the course of my college career, I have nights when I had the misfortune on receiving as little as one hour of sleep. Although I understand the relationship between the two factors, I think that perhaps there is a certain threshold of sleep deprivation before the amygdala begins to be overactivated.