Although REM Sleep Behavior Disorder (RBD) typically occurs in patients in their 50s, doctors are noticing a trend of more frequent RBD in 30-something patients taking antidepressants.
During REM sleep, muscles are usually paralyzed, but antidepressants may affect neurotransmitters that keep muscles paralyzed -- allowing for RBD to occur, say researchers at the Mayo Clinic.
"Our findings suggest that RBD in younger patients -- in the 30s instead of the usual age of the 50s or older -- is frequently linked to antidepressant use," lead researcher Dr. R. Robert Auger, sleep medicine specialist at the Mayo Clinic, said in a prepared statement.
But he cautioned that the findings can have multiple interpretations.
"I'd interpret this to mean one of three things: 1) in younger patients, antidepressants can cause RBD, or 2) in younger patients, RBD results in psychiatric diagnoses that then result in antidepressant prescriptions, or 3) a common factor is causing both the RBD and the psychiatric diagnoses, which in turn results in antidepressant prescriptions," Auger said.
"If medications are implicated in a direct manner, it may be an idiosyncratic effect, it could be related to the dose of the medication, or the medications simply may be unmasking an underlying predisposition to RBD," the Mayo expert added.
Researchers studied 20 patients under the age of 50 between 2002 and 2005 who had been diagnosed with RBD. Patients with neurological diseases such as Parkinson's or dementia were excluded from the study. These patients were compared to patients over age 50 diagnosed with RBD.
Eighty percent of the younger RBD patients were being prescribed antidepressants, the researchers noted, while only 15 percent of RBD patients in the older age group were taking antidepressants. Females also appear more likely to experience RBD at a younger age -- 45 percent of the younger patients were female, compared to just 13 percent of older patients.
Findings from the study were to be reported Monday at the Associated Professional Sleep Societies' SLEEP 2006 meeting in Salt Lake City.
"From the results of our study, it appears that young-onset RBD is frequently associated with antidepressants. It nevertheless appears to be a relatively rare phenomenon, so I don't think one should hesitate to take an antidepressant based on this particular risk," said Auger. "Physicians should be aware of this potential side effect, however, particularly in patients who complain of sleep disturbances. I'm hoping these findings will create a greater awareness, as practitioners generally would not link medications with RBD."