Stress Seems to Block Deep Sleep

Stress may disrupt the natural rhythms of the body's nervous system during various stages of sleep, says a University of Pittsburgh study in the journal Psychosomatic Medicine.

The link between daytime stress and restless sleep is well established, but scientists are still investigating the exact ways that stress affects sleep.

This study found stressed sleepers wake up more often while they're sleeping and have fewer episodes of deep sleep.

Researchers monitored the heart rates of 59 healthy undergraduate students while they slept. Heart rate variations can provide clues about the activity of the involuntary nervous system, which directs the function of organs such as the heart and lungs.

To trigger stress during sleep, the researchers told half of the students they would have to deliver a 15-minute speech when they woke up. The topics would be chosen for them upon awakening, the students were told.

The researchers detected significant heart rate variations between the stressed and non-stressed students as they slept. The stressed group had changes in heart rate patterns during REM, or rapid-eye-movement, sleep -- the sleep phase when dreaming occurs -- and non-REM sleep.

The heart rate variability patterns detected in the stressed students were similar to those seen in people with insomnia. the study says, suggesting similar pathways of nervous system disruption.

More information

To learn more about insomnia, visit American Academy of Family Physicians.