Out of all the insomnia symptoms (others include waking up during the night, waking up too early, etc.), this study found that trouble falling asleep was the greatest—and only—predictor of cognitive impairment down the road. Researchers found that those who reported prolonged sleep latency in 2002 were more likely to display worse episodic memory (a type of long-term memory) and executive function (the ability to problem-solve and make decisions) at the 2016 check-in.
“These results,” Zaheed explains, “suggest that regular screening for insomnia symptoms may help with tracking and identifying people with trouble falling asleep in mid-to-late life who might be at risk for developing cognitive impairments later in life.”
It is worth mentioning that this association may also have something to do with depressive symptoms and vascular diseases in participants. Zaheed notes more research is needed to confirm whether insomnia intervention can actually help prevent or slow the progression of cognitive impairment.