Anxiety could alter the brain's sleep switch in teens, FIU study finds

New research could help scientists understand how anxiety disrupts sleep — and eventually inform new ways to treat it

MIAMI, Sept. 9, 2026 /PRNewswire/ -- Anxiety may change how the brain regulates sleep in preteens, according to a new Florida International University study that identifies a potential biological pathway connecting anxiety and sleep problems during a critical period of development.

The study, published in Scientific Reports, analyzed children ages 10 to 13 recruited across a range of anxiety severity. Researchers found that anxiety altered the relationship between sleep and the pineal gland — the small structure in the brain involved in producing melatonin and regulating the sleep-wake cycle.

Among highly anxious preteens, having more melatonin-producing pineal tissue was associated with taking longer to fall asleep and lower sleep efficiency. Anxiety also changed the relationship between pineal tissue volume and non-rapid eye movement (NREM) sleep — the stages when the body progresses from light to deep sleep.

"If your anxiety is elevated and you have a larger pineal gland, you're going to have worse sleep outcomes than if you are high anxiety with a small pineal gland," said Aaron Mattfeld, an FIU associate professor of psychology and cognitive neuroscientist who led the study.

Using high-resolution MRI scans and overnight sleep monitoring, researchers separated the pineal gland's melatonin-producing tissue from fluid-filled cysts. They found no significant relationship between anxiety severity and the size of the pineal gland, its cysts or its melatonin-producing tissue alone. Instead, anxiety changed how the volume of that tissue related to sleep.

Why it matters

Sleep problems and anxiety are closely connected and can escalate during the transition into adolescence. Yet researchers still do not fully understand the biological mechanisms linking them. Identifying how anxiety interacts with a part of the brain central to sleep regulation provides a new avenue for investigating that connection.

The findings point to the pineal gland and melatonin system as one potential piece of the puzzle. The study did not directly measure melatonin or establish that pineal gland differences cause anxiety or poor sleep. Future studies will need to directly measure melatonin and investigate how serotonin and norepinephrine systems may affect its production.

Understanding those mechanisms could ultimately help researchers develop new approaches to treating anxiety and its associated sleep problems.

What parents can do now

For parents navigating preteen sleep struggles, Mattfeld emphasizes that consistency is key: keep regular sleep schedules, maintain a cool and screen-free bedroom, and seek behavioral therapy rather than over-the-counter supplements if issues persist.

"We need to help kids find that 'Goldilocks' amount of sleep," Mattfeld said, "because the brain is doing remarkable, necessary work while they rest."

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Media Contact:
Michelle Arean
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[email protected]
news.fiu.edu
@FIU

SOURCE Florida International University