Insomnia (and Meth?) Keeps the Brain Stuck in Daytime Mode

[Chip (OP)]

https://neurosciencenews.com/insomnia-circadian-dysfunction-29996/

Insomnia (and Meth?) Keeps the Brain Stuck in Daytime Mode

(Editor: Methamphetamine also causes Insomnia)

December 1, 2025

Summary:
People with chronic insomnia show a delayed and weakened daily rhythm of mental activity, keeping the brain in a more alert, daytime-like state at night. Under tightly controlled conditions, individuals with insomnia failed to show the normal nighttime drop in goal-directed thinking seen in healthy sleepers.

Their peak cognitive activity also shifted roughly six and a half hours later than normal. These findings suggest insomnia involves a biological timing problem in how the brain powers down, not just behavioral difficulty falling asleep.

Key Facts

● Circadian Shift: Mental activity peaks occur hours later in people with insomnia.

● Blunted Nighttime Shutdown: The expected drop in cognitive engagement during night is reduced.

● Treatment Implications: Strengthening circadian rhythms may improve sleep outcomes.

Source: University of South Australia

Australian researchers have found compelling evidence that insomnia may be linked to disruptions in the brain’s natural 24-hour rhythm of mental activity, shedding light on why some people struggle to ‘switch off’ at night.

Published in Sleep Medicine, the study led by the University of South Australia (UniSA) is the first to map how cognitive activity fluctuates across the day in individuals with chronic insomnia, compared to healthy sleepers.

The article continues at the link at the top ...