Moza K Bin Kamil AlShamsi

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia in which the normal muscle atonia of REM sleep is lost, and patients act out their dreams.Serotonergic antidepressants such as selective serotonin reuptake inhibitors (SSRIs) are a recognized trigger, but in psychiatric patients the nocturnal behaviors are easily attributed to stress or to the primary illness.We report the case of a 46-year-old man with schizoaffective disorder, depressive type, maintained on aripiprazole 15 mg daily, who was started on escitalopram 10 mg at bedtime (day one); the dose was reduced to 5 mg on day 77.Around day 430, about 14 months after starting escitalopram and while taking 5 mg, he began to walk in his sleep and act out his dreams, including punching movements and, on one occasion, walking while holding a clothing iron, with no recollection on waking.The episodes occurred late in the night, with his eyes closed, two to three times a month and were accompanied by sleep paralysis and daytime sleepiness.His mental status examination and routine blood tests were unremarkable.He declined polysomnography and brain imaging, so a diagnosis of probable RBD, possibly associated with escitalopram, was made on clinical grounds; a non-REM parasomnia could not be excluded.On day 616, escitalopram was stopped and clonazepam 0.5 mg at bedtime was started at the same time.The episodes had stopped by day 665.Clonazepam was discontinued on day 772, and at the latest follow-up on day 1962 there had been no recurrence.Because clonazepam was started when escitalopram was withdrawn, the improvement cannot be attributed to stopping escitalopram alone, although the absence of recurrence after clonazepam was discontinued supports a role for the antidepressant.Clinicians who prescribe serotonergic antidepressants should take a sleep history from patients and their bed partners, arrange polysomnography where it is available, and review the suspected drug.