Differential impact on isolated REM sleep without atonia by varying antidepressant therapies

Background: REM sleep without atonia (RSWA) is characterized by increased phasic or tonic muscle activity in electromyography channels during polysomnography and usually causes REM sleep behavior disorder, but RSWA also exists within healthy populations without dream-enactment behavior, especially in psychiatric populations receiving antidepressant therapies. Evidence for differential impact of antidepressants on RSWA, and whether RSWA persists or resolves following changes in antidepressant therapy, remains limited. Case: We present a 56-year-old woman with depression undergoing 3 polysomnograms while receiving 3 different distinct antidepressants. Her first polysomnogram demonstrated elevated REM sleep without atonia while receiving a tricyclic antidepressant. Following a switch to fluoxetine, her second polysomnogram showed greater elevation of REM sleep without atonia After a subsequent therapeutic switch to buproprion, a third polysomnogram showed interval decrease in RSWA amounts, lower than the initial levels found during tricyclic antidepressant administration. Results/Outcomes: A switch from fluoxetine to bupropion was associated with markedly reduced RSWA amounts. Conclusion/Interpretation: The polysomnography findings in this case suggest that the type of antidepressant treatment differentially impacts levels of RSWA. The potential importance and implication to practicing psychiatrists is that bupropion, with selective action on dopamine reuptake rather than serotoninergic or acetylcholinergic neurotransmission, may have lesser tendency toward increasing REM sleep muscle activity levels. Additional prospective studies comparing polysomnographic RSWA in psychiatric populations are needed.