Not recalling dreams could signal early Alzheimer's risk

Centre for Healthy Brain Ageing (CHeBA), UNSW Sydney

A new study of more than 1,000 older adults has found that not remembering dreams may be linked to early biological changes associated with Alzheimer’s disease - and could help predict future cognitive decline.

The research, published in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, also found that non-dream recallers experienced cognitive decline at twice the rate of those who remembered their dreams.

Lead author and Research Fellow at UNSW’s Centre for Healthy Brain Ageing (CHeBA), Dr Darren Lipnicki, said the findings point to dream recall as a simple but powerful early indicator.

“Older people who don’t recall their dreams may already be showing early signs of Alzheimer’s disease, even if their memory still appears normal,” Dr Lipnicki said.

“These changes seem to reflect disruption in the brain’s default mode network - the same system involved in both dreaming and Alzheimer’s.”

The researchers identified strong links between poor dream recall and both the APOE ε4 gene - the biggest genetic risk factor for Alzheimer’s - and higher levels of a key blood biomarker, p-tau217.

Crucially, these links were independent of memory test performance.

“This isn’t just about forgetting dreams,” Dr Lipnicki said.

“It may indicate that the brain is producing fewer or less vivid dreams in the first place due to early neurodegenerative changes.”

Participants who reported no dream recall at the start of the study were also more likely to develop dementia over the following decade.

Because dream recall can be assessed with a single question, the researchers say it could offer a low-cost, scalable way to help identify people at risk much earlier than current methods.

“If someone notices they’ve stopped remembering their dreams later in life, it may be worth paying attention,” Dr Lipnicki said.

“It could be an early signal that something is changing in the brain.”

Senior author and Co-Director of CHeBA Professor Perminder Sachdev said the findings highlight an unexpected new avenue for early detection.

“Dreaming is a window into how the brain generates internal thought,” Professor Sachdev said.

“Our findings suggest that changes in this process may be one of the earliest detectable signs of Alzheimer’s disease - and a promising target for future research and prevention.”

www.cheba.unsw.edu.au

Heidi Douglass
[email protected]

(02) 9385 0410