Original Article Defining the borders between Sleep-Related Eating Disorder and Night Eating Syndrome Piergiuseppe Vinai a,⇑ , Raffaele Ferri b , Luigi Ferini-Strambi c , Silvia Cardetti a , Matteo Anelli c , Paola Vallauri a , Noemi Ferrato a , Marco Zucconi c , Gabriella Carpegna a , Mauro Manconi c,d a GNOSIS No-Profit Research Group, Cuneo, Italy b Sleep Research Centre, Department of Neurology I.C., Oasi Institute (IRCCS), Troina, Italy c Sleep Disorders Center, Department of Neurology, Scientific Institute and University Ospedale San Raffaele, Vita-Salute University, Milan, Italy d Sleep and Epilepsy Centre, Neurocenter (EOC) of Southern Switzerland, Civic Hospital, Lugano, Switzerland article info Article history: Received 11 July 2011 Received in revised form 3 October 2011 Accepted 7 November 2011 Available online 26 March 2012 Keywords: Night Eating Syndrome Sleep Relating Eating Disorder Polysomnography Psychopathology Diagnostic criteria Parasomnia abstract Objectives: Nocturnal eating is a common symptom of two clinical conditions with different pathogenesis and needing different therapeutic approaches: Sleep Related Eating Disorder (SRED) and Night Eating Syndrome (NES). The first is considered a parasomnia while the second is an eating disorder; however, the distinction between SRED and NES is still a controversial matter. The aim of this study was to better define psychological, behavioral, and polysomnographic characteristics of the two syndromes. Methods: An eating disorders’ specialist tested a group of 28 nocturnal eaters diagnosed as affected by SRED by a sleep expert, following the current criteria of the international classification of sleep disorders, to find out if any of them was affected by NES according to the criteria suggested by both sleep and eating disorders specialists during the first international meeting on Night Eating Syndrome (Minneapolis, 2009) and if they had specific psychological or polysomnographic characteristics. Results: Twenty-two subjects were diagnosed to be affected by NES. They scored higher on the physical tension subscale of the Sleep Disturbance Questionnaire (SDQ) and on the mood and sleep subscale of the Night Eating Questionnaire (NEQ), but there were no other significant differences between SRED and NES patients nor for age, Body Mass Index (BMI), or gender distribution. Conclusions: The overlap between the symptomatology and the polysomnographic characteristics of the two pathologies and the difficulty in making a differential diagnosis between NES and SRED indicate the need for an update of the diagnostic criteria for SRED, as was recently done for NES. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Nocturnal eating is an unusual behavior shared by subjects with Sleep-Related Eating Disorder (SRED) and Night Eating Syndrome (NES). The level of awareness during the nocturnal food intake rep- resents the main feature that should distinguish SRED from NES. Indeed, the distinction between SRED and NES is still a controver- sial matter and some authors consider these diseases to be posi- tioned at opposite poles of a continuous clinical spectrum. The last revision of the International Classification of Sleep Dis- orders (ICSD-2) [1] defined SRED as a parasomnia characterized by recurrent episodes of nocturnal eating during a variable, usually reduced, state of alertness occurring after sleep onset, which are not linked to daytime eating disturbances such as bulimia nervosa, binge-eating disorder, or anorexia nervosa. The presence of recur- rent episodes of eating and drinking occurring during the main sleep period was established as the core symptom of SRED, which has to be accompanied by one or more of the following additional features: consumption of strange items, insomnia, sleep-related in- jury, occurrence of dangerous behaviours in the search for food, morning anorexia, and adverse health consequences related to nocturnal eating. As mentioned above, the issue of the level of con- sciousness during episodes of nocturnal eating is simply addressed by using the term ‘‘involuntary’’ eating. Moreover, the criteria sug- gested to diagnose NES are not updated. Those considered by the ICDS2, ‘‘overeating between the evening meal and nocturnal sleep onset, eating during complete awakenings from sleep with full subsequent recall, absence of biz (or toxic) food and substance 1389-9457/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.sleep.2011.11.017 Abbreviations: BMI, Body Mass Index; DSM-IV TR, Diagnostic and Statistical Manual of Mental Disorders; EDI-2, Eating Disorder Inventory (second edition); EMG, Electromyogram; ISI, Insomnia Severity Index; ICSD-2, International Classi- fication of Sleep Disorders; NEQ, Night Eating Questionnaire; NEDS, Nocturnal Eating and Drinking Syndrome; PSWQ, Penn State Worry Questionnaire; SAS, Self Rating Anxiety Scale; SDS, Self Rating Depression Scale; SDQ, Sleep Disturbance Questionnaire; SRED, Sleep Relating Eating Disorder; V-PSG, Video-polysomno- graphic study. ⇑ Corresponding author. Address: v Langhe 64, 12060 Magliano Alpi, CN, Italy. Tel.: +39 3386946679. E-mail address: piervinai@tin.it (P. Vinai). Sleep Medicine 13 (2012) 686–690 Contents lists available at SciVerse ScienceDirect Sleep Medicine journal homepage: www.elsevier.com/locate/sleep