Sleep-related eating disorder and zolpidem: an open interventional cohort study.

To the Editor: Sleep-related eating disorder (SRED) is a newly recognized parasomnia that describes a clinical condition of compulsive eating under an altered level of consciousness during sleep. The prevalence rate varies from 4% to 16.7% among different clinical psychiatric populations.1,2 The exact etiology of SRED is unclear, but it is postulated that SRED might share features of both sleepwalking and eating disorders.3 In addition, there have been accumulating reports of SRED related to the use of various psychotropic medications including triazolam, zolpidem, olanzapine, risperidone, and combinations of psychotropics.4–8 Among these drugs, recent attention has focused on zolpidem, a nonbenzodiazepine hypnotic. Our clinical epidemiologic study in psychiatric outpatients2 showed that 1 out of 7 subjects regularly taking zolpidem could develop SRED in their lifetime. In addition, among a psychiatric population, most of the adult-onset sleepwalking cases were highly comorbid with SRED features.9 Thus, there seems to be a robust association of zolpidem and SRED on the basis of both cross-sectional clinical series and epidemiologic evidence. Warnings were issued in 2007 by both the Therapeutic Goods Administration of Australia10 and US Food and Drug Administration11 with regard to SRED as a potential side effect of zolpidem. Nonetheless, in order to confirm a definite association of zolpidem and SRED, resolution or reduction of SRED symptoms upon cessation of zolpidem treatment should be demonstrated. In particular, the episodic nature of the SRED attacks would argue the need for a longer-term follow-up period to document a clear resolution of the symptoms.