HELSINKI, June 23, 2025 -- New research presented today at the European Academy of Neurology (EAN) Congress 2025 reveals that frequent nightmares are associated with significantly accelerated biological ageing and a more than threefold increase in the risk of premature death. This study is the first to show that nightmares independently predict faster biological ageing and earlier mortality – even after accounting for other health issues. 

Led by Dr Abidemi Otaiku of the UK Dementia Research Institute and Imperial College London, the study analysed data from 2,429 children aged 8 to 10 and 183,012 adults aged 26 to 86 across six long-term population cohorts.

Nightmare frequency in adults was self-reported at the start of the study, with participants followed for up to 19 years. For children, nightmare frequency was reported by their parents at the beginning of the study.

Results showed that adults reporting weekly nightmares were more than three times as likely to die prematurely (before age 70) compared to those who rarely or never experienced nightmares. Children and adults with more frequent nightmares also exhibited faster biological ageing, which accounted for approximately 40% of the heightened mortality risk.

Notably, weekly nightmares were found to be a stronger predictor of premature death than other established risk factors such as smoking, obesity, poor diet, and low physical activity. 

"Our sleeping brains cannot distinguish dreams from reality", Dr Otaiku explained. "That's why nightmares often wake us up sweating, gasping for breath, and with our hearts pounding – because our fight-or-flight response has been triggered. This stress reaction can be even more intense than anything we experience while awake." 

He continued, "Nightmares lead to prolonged elevations of cortisol, a stress hormone closely linked to faster cellular ageing. For those who frequently experience nightmares, this cumulative stress may significantly impact the ageing process. Additionally, nightmares disrupt both sleep quality and duration, impairing the body's essential overnight cellular restoration and repair. The combined effects of chronic stress and disrupted sleep likely contribute to the accelerated ageing of our cells and bodies."

The association between frequent nightmares and accelerated ageing remained consistent across all ages, sexes, ethnicities, and mental health statuses, indicating a universal effect. Even monthly nightmares were linked to faster ageing and increased mortality compared to rare or no nightmares, emphasising the importance of reducing nightmare frequency across the population.