The research is the first to look at the association between these sleep symptoms and mental health in student athletes, independent of insufficient sleep or insomnia.
The findings show that hypnogogic/hypnopompic hallucinations — dream-like experiences that occur while falling asleep or waking up — were reported by 24 percent of the athletes, while 11 percent said that they experience these symptoms at least once per week.
In addition, occasional sleep paralysis was reported by 18 percent of the sample, and 7 percent reported that this happens at least once per week.
Compared to athletes who had never experienced sleep paralysis or hypnogogic/hypnopompic hallucinations, those who did experience them, even rarely, also reported higher depression scores. The findings remained even after controlling for how much sleep or what quality of sleep the person experienced.
“These symptoms are often thought to be relatively harmless and quite rare. But they can be very distressing to those who experience them, and they may be surprisingly common among student athletes,” said senior author Michael Grandner, Ph.D., M.T.R., the director of the Sleep and Health Research Program and assistant professor of psychiatry at the University of Arizona College of Medicine.
“What was also surprising was that the degree to which people reported these symptoms predicted severity of depression symptoms, even after controlling for poor sleep and lack of sleep, which can contribute to both depression and these types of sleep symptoms.”
The data was taken from 189 NCAA Division-I student athletes, who were asked to report how often they experienced the symptoms of sleep paralysis and hypnogogic/hypnopompic hallucinations. The young athletes were also asked about sleep duration, and they completed the Insomnia Severity Index and the Centers for Epidemiological Studies Depression Scale.
Due to a busy schedule, student athletes often struggle to find time to rest. Thus, shorter sleep duration and poor sleep quality tend to contribute to disordered sleep in many student athletes. In addition, sleep symptoms such as sleep paralysis and hallucinations are more common in younger adults.
The preliminary findings of this study suggest that these symptoms may be warning signs of another medical problem.
“These sleep symptoms are usually harmless on their own, but they can be a sign of more serious sleep problems,” said lead author Serena Liu, a student research assistant in the Sleep and Health Research Program directed by Grander. “The fact that they are so common among student athletes suggests that this is a group with some significant sleep problems that should be evaluated and dealt with.”
The study was published in an online supplement of the journal Sleep and was presented at SLEEP 2018, the 32nd annual meeting of the Associated Professional Sleep Societies LLC (APSS).