Prevalence of nightmares among the general finnish adult population and veterans of the second world war

Abstract

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 35year study period. We also investigated the associations between nightmares and various factors 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 5years 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 30days. The surveys also contain questions about various topics related to mental and physical health. The statistical methods used include Pearson and Mantel–Haenszel χ 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 difference 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 prevalence 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).