All of these people suffered an unusual sleep disorder in which they act out violent dreams. It's called REM-sleep behavior disorder, or RBD. Most people who suffer RBD are men — and most are over 50 years old.
But some people get RBD at a much younger age. What makes them different from people without RBD? A Mayo Clinic research team including R. Robert Auger, M.D., took a close look at 22 young RBD patients. They compared them with 22 age- and sex-matched people with a different sleep disorder, obstructive sleep apnea. They also compared them to older RBD patients.
"Eighty-percent of this early onset RBD group were using antidepressants vs. 15 percent of age- and gender- matched non-RBD controls," Auger tells WebMD. "And we found antidepressant use was much higher in the younger group than in the older group of RBD patients."
Auger reported the findings at this week's annual meeting of the Associated Professional Sleep Societies' SLEEP 2006 meeting in Salt Lake City.
Antidepressants Not Proven RBD Cause
What makes RBD different from sleepwalking is that it happens only during dreams. Dreams occur in the second half of the sleep cycle, during REM — rapid eye movement — sleep. Sleepwalkers, in contrast, aren't dreaming, and usually begin their nocturnal activity soon after bedtime.
During normal REM sleep, the brain shuts down the body's ability to move — except for eye movement and the muscles needed for breathing. But this virtual paralysis doesn't happen in people with RBD.
In fact, about half of people with late-onset RBD symptoms actually have Parkinson's disease or a Parkinson's-like movement disorder. Some two-thirds of people with true late-onset RBD, Auger says, eventually develop one of these degenerative brain diseases.
Recently, researchers have found that antidepressants affect REM sleep. So one explanation for the study findings is that in some people, antidepressants cause RBD. Auger is quick to point out that this isn't the only explanation. People take antidepressants because they have psychiatric symptoms. This underlying illness could also be triggering RBD.