Increased REM sleep latency and Alzheimer’s disease: important risk factor or red herring?

I’ve often highlighted the importance of quality sleep for cognitive health, but might certain sleep metrics actually serve as an indicator of neurodegenerative disease? In light of a recent study reporting a correlation between increased REM sleep latency (the amount of time between becoming unconscious and entering REM sleep) and the severity of neurodegenerative biomarkers in Alzheimer’s disease (AD),¹ some health influencers believe the answer is “yes” — and they’ve even gone so far as to advocate for using REM sleep latency…