Effects of Anxiety on Sleep Are Different Than Depression

By Alexander Golbin, M.D.

There is a robust research finding that proves significant disorganization of sleep architecture (meaning changes in the quantity and quality of sleep) in depressed patients.

Several abnormalities have been documented in depressed patients such as: decreased sleep continuity (fragmented sleep), diminished slow wave sleep (NREM) and alterations of rapid eye movement (REM) sleep, including decreased REM latency (too early onset), and increased REM density.

In contrast to the attention focused on sleep in patients with affective disorders, relatively little research has focused on sleep disturbances in anxiety patients. Available findings did show significant sleep problems in various types of anxiety patients, such as in Post-Traumatic Stress Disorder (PTSD), panic disorder and Generalized Anxiety Disorder (GAD). In general, these studies revealed patterns of decreased sleep efficiency, disrupted course of sleep, and an overall lightening of sleep.

Sleep research with anxiety was performed mostly on patients who suffer not only with anxiety, but also with other psychiatric problems.

Researchers from the Louisiana State University studied sleep by polysomnography of 15 adult subjects with "pure" anxiety in the absence of any other psychiatric problems and 15 adults as a control group.

Results of objective polysomnographic studies showed that individuals with high anxiety and worries, even without depression or other psychiatric problems, have documented changes: It took them longer to fall asleep. When they sleep, the percentage of NREM sleep (that is a resting sleep in which growth hormone is released) is decreased with more frequent transitions from deep sleep to light sleep (stage 1 of NREM), more microarousals and a lower REM density (frequency of rapid eye movements per unit of time).

If in depressed patients REM sleep is started earlier and is more intense (higher REM density), in anxiety patients REM started later and was less prominent. The disruptions are mostly during the first half of the night.

Disruptions of the early portions of sleep are critical to restorative sleep and might cause chronic fatigue.