Antidepressants linked to sleep disorder that causes dreamers to act out their dreams

As seen in the News Sentinel

Living out your dream is one thing.

But acting out your dreams when you're still asleep?

Ouch!

People who do that have REM behavior disorder, and it's potentially dangerous.

"I once had someone who choked his wife until she was almost blue. He was dreaming he was choking a burglar," said Ann Romaker, director of the Sleep Disorders Center at St. Luke's Hospital.

It's also a disorder that researchers suspect may be on the rise as one of the odder and rarer side effects of the broad use of antidepressant medications.

"It's actually not that surprising, knowing what these medications do chemically in the brain," said psychiatrist R. Robert Auger of the class of antidepressants that includes Effexor, Prozac, Zoloft, Paxil and other serotonin reuptake inhibitors.

Auger, a sleep researcher at the Mayo Clinic in Rochester, Minn., presented findings on the link between antidepressants and REM behavior disorder last summer at a meeting of sleep researchers. But his work is also part of a broadening interest in a sleep disorder once thought to be an irksome curiosity.

Scientists, for example, have long known that some people who have Parkinson's disease may also suffer REM behavior disorder, acting out their dreams in their sleep, sometimes falling out of bed.

More and more, researchers are coming to believe that, for a small percentage of people, the sleep disorder may also be one of the earlier signs of a Parkinson's disease that has yet to develop. Some studies show that more than 10 to 25 percent of people with REM behavior disorder later develop Parkinson's or some other neurodegenerative disease. Researchers caution that the connection is anything but certain.

"I don't think we need to frighten people," Romaker of St. Luke's said. "I have been dealing with this for 18 years, and most of my patients never go on to develop anything else."

Sleep experts have known about the REM behavior disorder for years.

Auger called it a relatively rare phenomenon. About 0.5 percent of people have it. More than 90 percent of cases occur in men older than 50. But, possibly because of the rise in antidepressant use, younger men, women and children have begun to complain of the disorder.

"We had a 10-year-old boy who had had terrible REM behavior disorder," said Mark Mahowald, a leading researcher on the disorder at the Minnesota Regional Sleep Disorder Center in Minneapolis. "He was being given Effexor for some nondescript learning disorder and was falling out of bed constantly. When you see a 10-year-old boy with REM behavior disorder, you can bet that the first 10 causes are antidepressants, anti depressants, anti depressants."

REM sleep, or rapid-eye movement sleep, is the time in the sleep cycle when people have their most robust dreams. During REM - unlike other periods in the sleep cycle - the brain normally paralyzes the skeletal muscles so that body doesn't run around while sleeping. But this doesn't happen in REM behavior disorder.

Scientists don't know the exact mechanism, but they suspect antidepressants are acting on neurochemicals in the brain stem that typically cause what's known as REM sleep paralysis or atonia. People who later go on to develop Parkinson's may be getting REM behavior disorder early because certain cells in the brain have begun to deteriorate.

REM behavior disorder usually comes to the attention of physicians only after someone has tossed himself out of bed during an active or violent dream or, more common, after inadvertently assaulting a sleeping spouse.

"One of my patients was hitting his wife in the night, and he didn't know it," Romaker said. "They came to me in their 80s. This had been going on for years. His poor wife had never told him until she had a black eye. She didn't want to hurt his feelings. She worried it was due to some repressed feelings he had never told her about."

The range of behaviors is as vast as dreams themselves.

"It can be as simple as someone who sits up at night and turns pages because they're dreaming they're reading a book," Romaker said. "I had one gentleman who thought he was fishing. He was gutting a fish, and he was trying to gut his wife. It was fortunate he didn't actually have anything sharp."

Other patients have hurled themselves from their beds while dreaming of swimming or diving. One of Romaker's patients punched his wife during a dream about fighting a schoolyard bully.

Bob Whitman, director of the Sleep Disorders Center at the University of Kansas Hospital, had one patient who was so tired of getting up and bumping into furniture during her dreams, "she would tie herself to the bed," he said. "She had done this for several years so she wouldn't get out."

"Their behavior is completely consistent with the dream," Romaker said. Unlike patients who sleep walk or have night terrors, which don't occur during REM sleep, patients with REM behavior disorder are much easier to wake.

It's unclear how many women have REM behavior disorder. Romaker suspects that it's vastly under diagnosed simply because women may not have dreams that are as violent or active as men's.

Fortunately, REM behavior disorder tends to be treated easily, typically with a prescription tranquilizer such as clonazepam. Those who suffer REM behavior disorder because of antidepressants can often be switched to another antidepressant such Wellbutrin, which does not appear to trigger the disorder.

"I don't think its any reason to fear taking antidepressants," Auger of the Mayo Clinic said. "I just think it's something people need to be aware of."