Researchers have found that the effects of sleep disorders are not limited to the tiredness and exhaustion we usually feel after a night of sleep deprivation, but extend to real structural changes in the brain itself.
This was revealed by a new study from Florida International University, which analyzed 57 brain imaging studies, providing one of the most comprehensive looks to date at how sleep problems affect brain structure and function.
To better understand what is happening in the brain across a variety of sleep disorders, researchers at the University's Children and Families Center conducted a comprehensive meta-analysis, one of the first studies to examine multiple types of sleep disorders side by side, looking for common and distinctive patterns in brain structure.
Researchers have classified the disorders into two main categories: the first is "sleep disorders," which include insomnia and sleep apnea, disorders that make it difficult to fall asleep or stay asleep; the second is "sleep abnormalities," which include sleepwalking, nightmare disorder, and night terrors, disorders that disrupt the sleep cycle itself.
Across both groups, researchers identified significant reductions in the thalamus, a brain region crucial for filtering information, maintaining focus, and supporting higher-level thinking.
More specifically, they found structural changes in a part of the thalamus known as the "posterior geniculate nucleus," which helps direct attention and regulate cognitive control.
These changes, it turns out, are linked to broader brain networks involved in concentration and task performance, helping to explain why disrupted sleep can contribute to slower responses, poorer decision-making, and an increased risk of errors and accidents.
But the study didn't stop there; it also revealed unique patterns specific to sleep disorders. Researchers found structural changes in the posterior cingulate cortex, a region involved in motivation, decision-making, and emotional regulation. These findings may help explain why people with sleep disorders sometimes experience changes in mood, behavior, and emotional control.
In contrast, the researchers did not find consistent structural changes specific to sleep disorders, suggesting that different sleep disorders may affect the brain in distinct ways depending on how sleep is disrupted.
Matthew Sutherland, a cognitive neuroscientist at the university and the study's first author, commented: "As people become more aware of the importance of sleep, there is a pressing need to understand what is happening in the brain."
By combining the results of numerous studies, this research gives us a clearer picture of how sleep disorders affect brain structure and function, and where we need to focus next. Catherine Crooks, a newly awarded PhD in cognitive neuroscience and the study's lead author, added: "Most research looks at sleep disorders individually. But by looking across many studies, we found common patterns in the brain that help explain why sleep problems can affect focus, decision-making, and daily performance. With so many people struggling with sleep problems, understanding what's happening in the brain is key to finding better interventions, diagnostic tools, and personalized treatments."
The research team hopes these findings will help guide future interventions designed not only to improve sleep but also to protect brain systems that support attention, decision-making, and emotional regulation. In their next step, the researchers plan to investigate specific types of sleep abnormalities, such as sleepwalking and REM sleep behavior disorder, and explore whether the observed brain changes are a cause of these sleep disturbances, a consequence of them, or both.
