A 70-year-old non-addict man with the history of diabetes, hypertension and allergic rhinitis was referred for abnormal behavior during the night. The behaviors included shouting, punching, walking during sleep, leaving the house and dream enactment. He also had history of snoring and excessive daytime sleepiness, suspicious of obstructive sleep apnea (OSA). He was suffering from depression for which he was on antidepressants, i.e., mirtazapine, sertraline and olanzapine by a psychiatrist. The abnormal sleep behaviors developed after start of mirtazapine. After ruling out all other causes, he was finally diagnosed to be suffering from drug-induced parasomnia overlap disorder (POD) caused by mirtazapine along with OSA based on international classification of sleep disorders–3rd edition (ICSD-3). He had resolution of the parasomnia episodes after stoppage of mirtazapine.
Meghna P. Mansukhani, Bhanu Prakash Kolla, Kannan Ramar. American Academy of Sleep Medicine. International classification of sleep disorders. 3rd ed. Darien, IL: American Academy of Sleep Medicine; 2014 Mar; 9(1):1-11.
Winkelman JW, James L. Serotonergic antidepressants are associated with REM sleep without atonia. Sleep 2004 Mar 15;27(2):317-321.
Onofrj M, Luciano AL, Thomas A, Iacono D,D'Andreamatteo G. Mirtazapine induces REM sleep behavior disorder (RBD) in parkinsonism. Neurology. 2003 Jan 14;60(1):113- 115.
Yeh YW, Chen CH, Feng HM, Wang SC, Kuo SC, Chen CK. New onset somnambulism associated with different dosage of mirtazapine: a case report. Clin Neuropharmacol. 2009 Jul 1;32(4):232-233.
Faridhosseini F, Zamani A. A Case Report of Somnambulism Associated With Olanzapine. Iranian Journal of Psychiatry and Behavioral Sciences. 2012 Spring Summer;6(1): 72-74.
Schenck CH, Boyd JL, Mahowald MW. A parasomnia overlap disorder involving sleepwalking, sleep terrors and REM sleep behavior disorder in 33 polysomnographically confirmed cases. Sleep1997 Nov 20; 20(11): 972–981.
Dumitrascu O, Schenck CH, Applebee G, Attarian H. Parasomnia overlap disorder: a distinct pathophysiologic entity or a variant of rapid eye movement sleep behavior disorder? A case series. Sleep Med. 2013 Nov 1; 14(11):1217- 1220.
Markov D, Jaffe F, Doghramji K. Update on Parasomnias: A Review for Psychiatric Practice. Psychiatry (Edgmont). 2006 Jul;3(7):69-76.
Esaki Y, Kitajima T, Fujishiro H, Fujita S, Hirose M, Watanabe A, Iwata N. Parasomnia overlap disorder caused by paroxetine. Sleep Biol. Rhythms. 2017 Jun 21;15(4):327-329.
Schenck CH, Mahowald MW. Parasomnias associated with sleep-disordered breathing and its therapy, including sexsomnia as a recently recognized parasomnia Somnologie. 2008 Mar 1;12(1):38-49.
Schenck CH, Boeve BF, Mahowald MW. Delayed emergence of a parkinsonian disorder or dementia in 81% of older males initially diagnosed with idiopathic REM sleep behavior disorder (RBD): 16 year update on a previously reported series. Sleep Med. 2013 Aug 1;14(8):744-748.
