Stressed Say Sleep Suffers but Study Casts Doubts

Newswise — Stress may not negatively impact sleep quality as much as previously believed.

That's what a study by three students—Katrina Clemens, Amanda Hoover, and Marissa Kosydor— at Mansfield University in Mansfield, PA suggests. They were supervised by Mansfield University Psychology Professor Francis Craig and presented their findings March 10-12 in Boston at the annual meeting of the Eastern Psychological Association.

"According to previous research, greater stress has been correlated with a poor night's sleep as measured by a variety of self-reported sleep quality variables," Dr. Craig says.

"There is, however, little research that objectively measures the relationship between sleep quality and stress perception. This study sought to address this gap by measuring the relationship between sleep and stress using both objective and self-reported means of assessing of sleep quality."

The student researchers surveyed 27 persons who rated their own sleep quality and stress levels using two instruments: the Pittsburgh Sleep Quality Inventory (PSQI) and the Perceived Stress Scale (PSS). From that pool, seven participants who reported high levels of stress and seven who reported low levels of stress were recruited to have their sleep assessed for one night-time sleep period while connected to the Actigraph Mini-Motion Logger® with Action-W® sleep analysis software, which measures a person's amount of movement.

Those who perceived their levels of stress to be high reported their own sleep quality to be poor. The motion logger, however, showed little difference in sleep quality between those with high levels and low levels of stress.

"Like other studies before it, this research showed that high stress self-perception is directly related to self-reported sleep quality," says Dr. Craig. "When assessed using Motion Logger, however, little difference was found between those with high levels and low levels of stress. This suggests that stress may affect the perceived quality of sleep, not the behavioral quality of sleep."

In the past, studies on the impact of stress on quality of sleep typically have included only subjective measurements such as the PSQI and the PSS which rely on a person's perceptions. This study, however, was unusual in the fact that it incorporated objective measurements including the number of times the participant woke up, the amount of movement during sleep, and the percentage of time actually spent sleeping when in bed.

"Future research will need to be done using a much larger sample size where participants are observed over a longer duration of time," says Craig. "Observing fourteen people for one night is not a sufficient sample size or time period to find a representative sample of participant sleep quality. It does, however, suggest a promising avenue for sleep research."

The students received a $300 prize from Psi Chi, the national honor society of psychology, for their study which was titled "Is Perceived Stress Related to Objective and Subjective Sleep Quality?"