Nightmares are vivid, negative dreams that awaken the dreamer. While occasional nightmares are common, frequent ones often indicate underlying emotional regulation problems. A genome-wide association study of 45,255 individuals found no single genetic variants linked to nightmare frequency, but estimated heritability at 5%. Genetic correlation analysis revealed strong correlations between nightmares and anxiety, depressive disorders, posttraumatic stress disorder, and the personality trait neuroticism. Mendelian randomization suggested that insomnia may causally increase the likelihood of frequent nightmares. These findings indicate that nightmares share genetic factors with psychiatric conditions and that insomnia may heighten susceptibility to nightmares, highlighting the need for systematic nightmare assessment in clinical settings.
Nightmares are vivid, disturbing dreams that wake the dreamer. Twin studies show nightmare frequency is 36–51% heritable. A genome-wide association study of 28,596 individuals from Finland and the United States identified genetic variants near MYOF and PTPRJ (a gene previously linked to sleep duration) that predispose to nightmares. Strong genetic correlations were found between nightmare frequency and neuroticism, post-traumatic stress disorder, major depressive disorder, daytime sleepiness, and insomnia. Mendelian randomization indicated that feelings of being fed-up, nervous, and miserable cause nightmares, with no evidence that nightmares cause psychological problems. The findings suggest nightmares arise from unique genetic risk factors and are substantially caused by underlying psychological and sleep problems.