reaction time in the morning showed no significant difference between the two groups. Conclusion: Our results demonstrate that while subjects with sleep-disordered breathing show similar initial learning (encoding) on a declarative memory task compared to healthy controls, they perform significantly worse after a night of sleep. The higher amount of slow wave sleep in the control group seen only during the test night suggest that the lack of sleep-dependent consolidation in the OSA group may be due to the inability to generate a post-training increase in slow wave sleep, which is associated with more efficient memory consolidation. Acknowledgements: This work was supported by K23 HL103850- 01, American Board of Sleep Medicine Junior Faculty Research Award # 54-JF-1-10. http://dx.doi.org/10.1016/j.sleep.2013.11.041 Prevalence of nightmares among the general finnish adult population and veterans of the second world war N. Sandman 1 , K. Valli 2 , E. Kronholm 3 , H. Ollila 3 , T. Laatikainen 3 , T. Paunio 3 1 University of Turku, National Institute of Health and Welfare, Finland 2 University of Turku, Finland 3 National Institute of Health and Welfare, Finland Introduction: Nightmares are emotionally negative intense dreams and a relatively common phenomenon. Most people experience occasional idiopathic nightmares which are completely benign, but frequent nightmares are associated with mental health problems and increased suicide risk and can be a serious mental health issue. The current research investigates the prevalence of nightmares among the Finnish general adult population as well as veterans of the Second World War. Specifically, we were interested how sex, age and war experiences affect the nightmare prevalence and how the prevalence has changed during the 35 year study period. We also investigated the associations between nightmares and various fac- tors including other sleep problems, mental and physical health and lifestyle. Materials and methods: The current research is based on the National FINRISK Study which includes health surveys conducted every 5 years from 1972 to 2012. The surveys consist of independent random population samples of Finnish adults aged 25–74 (N = 75,647). The question about nightmares is self-assessment of frequency during the last 30 days. The surveys also contain ques- tions about various topics related to mental and physical health. The statistical methods used include Pearson and Mantel–Haenszel v 2 , Cramer’s V and Logistic regression. Results: In the whole sample, 3.5% of men and 4.8% of women report frequent nightmares, but the prevalence and the sex differ- ence is significantly affected by the age of participants. Occasional nightmares have increased in Finland from 1972 to 2007 and the effect of the Second World War can be seen in nightmare preva- lence still decades after the war in the surveys of 1972–1987. Among war veterans the prevalence of nightmares is significantly higher at 7.0% than among their peers without war experience. Significant correlates of nightmares include depression, insomnia and stress. Conclusion: Nightmares are not uncommon among Finnish adults and their prevalence is affected by sex, age, historical time and war experiences. They are also associated with other sleep problems and poor mental health. Our research leads to better understanding of the interindividual variation in nightmare frequency. Acknowledgements: This work has received financial support from Jenny and Antti Wihuri Foundation, Sigrid Juselius foundation and Turku Institute of Advanced Studies (TIAS). http://dx.doi.org/10.1016/j.sleep.2013.11.042 ’’I cannot sleep if i don’t eat’’ A dysfunctional beliefs could sustain nocturnal eating P. Vinai Studi Cognitivi, Milano, Italy Introduction: Nocturnal eating is an unusual behavior shared by patients affected by Night Eating Syndrome and Sleep Related Eating Disorder, the differential diagnosis between the two pathologies is frequently not easy. A pathognomonic symptom of NES is the pres- ence of the believe that one must eat in order to fall asleep. The pres- ence of this conviction was included among the diagnostic criteria for NES published in 2010. In this study we evaluated if this convic- tion is significantly more present among obese patients suffering from insomnia and nocturnal eating, than among obese patients with insomnia who do not eat at night. Materials and methods: Ninety-eight obese subjects afflicted by insomnia were included in the study. Eight were affected by NES, 33 by Binge Eating Disorder (BED), and thirteen by both BED and NES. Subject’s insomnia and sleep disturbances were assessed using the Insomnia Severity Index and the Sleep Disturbance Question- naire. The presence of the belief that one must eat at night was eval- uated with the question: ‘‘Do you need to eat in order to get back to sleep when you wake up at night?’’. Results: Patients affected by NES and by both BED and NES were convinced that nocturnal food intake is necessary in order to fall back asleep after a night time awakening. Conclusion: The presence of this belief seems to be a valid factor in identifying the presence of the Night Eating Syndrome among obese subjects suffering from insomnia. Acknowledgement: A sincere thanks to all the colleagues who sup- ported us during this research. http://dx.doi.org/10.1016/j.sleep.2013.11.043 Sleep enactment behaviors in Parkinson’s disease and multiple system atrophy: Beyond rem behavior disorder P. Ratti 1 , M. Sierra-Peña 2 , J. Bastin 3 , R. Manni 4 , M. Simonetta-Moreau 5 , O. David 3 1 Toulouse University Hospital, INSERM UMR 825, Department of Clinical Pharmacology, France 2 Toulouse University Hospital, INSERM UMR 825, Clinical Investigation Center CIC 9302, France 3 Grenoble Institute of Neurosciences, Brain Function & Neuromodula- tion, France 4 IRCCS Casimiro Mondino Institute of Neurology Foundation, Sleep and Epilepsy Unit, France 5 Toulouse University Hospital, INSERM UMR 825, Department of Physiology, France Introduction: Arousal-related ‘‘Sleep Enactment Behaviors’’ (SEBs) in Parkinson’s Disease (PD) and Multiple System Atrophy (MSA) con- sist of heterogeneous behaviors arising from NREM or REM sleep Their semeiological and electrophysiological aspects have not been e34 Abstracts / Sleep Medicine 14S (2013) e18–e92