Mood disorders affect sleep in Parkinson's disease

Depression and anxiety are associated with poor sleep quality, daytime drowsiness and nightmares in patients with Parkinson's disease, according to a recent report.

Although depression and anxiety affect 40 percent or more of patients with Parkinson's disease, just one study has looked at the impact of these conditions on sleep, Dr. Leora L. Borek, from Butler Hospital in Providence, Rhode Island, and colleagues note. Moreover, only quality of sleep was examined in that study.

The present study, reported in the Journal of Clinical Psychiatry, involved 120 consecutive Parkinson's patients who were seen at a movement disorder clinic between July 2004 and May 2005.

The patients all completed standard tests to assess depression and anxiety, as well as various aspects of sleep. Questionnaires and dream logs were used to evaluate the patients for nightmares and rapid eye movement sleep behavior disorder (RBD), a condition in which muscle tone persists during REM sleep.

On average, the subjects were 71 years of age and had Parkinson's disease for 7.3 years, the report indicates. More than half of the patients were male and 41.7 percent of subjects had a psychiatric history.

Nightmares occurred in 53.3 percent of the subjects and RBD was identified in 30 percent, the report indicates.

Severity of depression and anxiety were associated with poor sleep quality, daytime drowsiness and nightmares. Further analysis showed that the severity of depression strongly influenced sleep quality and the occurrence of nightmares, while the severity of anxiety affected daytime drowsiness.

"Increased recognition and effective management of depression and anxiety are likely to improve the quality of life for Parkinson's disease patients," the authors conclude.

SOURCE: Journal of Clinical Psychiatry, June 2006.