New research published in JAMA Open Network sheds light on how the brain is affected by both chronic sleep disorders and temporary sleep deprivation. The study found that people with long-term sleep disorders show consistent changes in regions linked to emotion and reward processing, while people who experience short-term sleep loss show distinct changes in the brain’s relay center, the thalamus. These findings suggest that while both types of sleep problems are associated with brain alterations, they affect different neural systems.
Sleep disorders and insufficient sleep are extremely common across the world, yet their biological effects are not fully understood. Poor sleep is a known risk factor for a variety of mental health conditions and often appears alongside neuropsychiatric disorders. Recent advances in brain imaging have helped researchers begin to map how poor sleep affects brain function and structure, but many questions remain unanswered. In particular, it was unclear whether chronic sleep disorders and short-term sleep deprivation share similar brain abnormalities, or whether they affect different systems altogether.
“We were interested in this topic because sleep disturbances are incredibly common and have a profound impact on daily functioning and mental health. Despite the high prevalence and the shared daytime symptoms, comorbidities, and even genetic risk factors across different sleep disorders, research has often focused on these conditions in isolation,” said study author Gerion Reimann of Aachen University Hospital.
“Similarly, studies on experiment-induced sleep deprivation in healthy individuals are rarely linked back to chronic sleep disorders, even though the possibility of overlapping brain mechanisms remains an ongoing topic of discussion. Compounding this, many neuroimaging studies suffer from small sample sizes and methodological heterogeneity. We wanted to address these gaps by investigating whether chronic sleep disorders and short-term sleep loss share common or distinct neurobiological substrates – and to do so in a robust, large-scale meta-analytic framework.”
The researchers conducted a large-scale multimodal neuroimaging meta-analysis. They systematically reviewed neuroimaging studies from several databases, including work on a range of sleep disorders like insomnia, obstructive sleep apnea, narcolepsy, and restless legs syndrome, as well as studies examining healthy individuals undergoing experimental sleep deprivation. In total, the analysis included data from 231 studies, encompassing 140 experiments and nearly 3,400 participants after accounting for overlapping samples. Only studies that used whole-brain structural or functional imaging and had significant findings comparing sleep-affected individuals to healthy controls were included.
The researchers used a method called activation likelihood estimation to find areas of the brain that consistently showed alterations across studies. Separate analyses were conducted for long-term sleep disorders and for short-term sleep deprivation. They also conducted contrast analyses to directly compare the two groups, as well as functional connectivity analyses to map how the affected brain regions interact with the rest of the brain.
The meta-analysis revealed that people with chronic sleep disorders consistently showed alterations in two brain regions: the bilateral subgenual anterior cingulate cortex (sgACC) and the right amygdala and hippocampus. These regions are heavily involved in emotion regulation, reward processing, and memory. In contrast, people who experienced short-term sleep deprivation showed consistent changes in the right thalamus, a region involved in regulating attention, sensory processing, and alertness.
Behavioral decoding analyses suggested that abnormalities in the subgenual anterior cingulate cortex were linked to reasoning, reward processing, and taste perception. Changes in the right amygdala and hippocampus were linked to negative emotions such as anger, anxiety, and sadness, as well as memory and respiratory interoception. The thalamus changes observed in sleep-deprived individuals were associated with thermoregulation, pain perception, and motor control.
Importantly, there was no evidence of overlapping abnormalities between long-term sleep disorders and short-term sleep deprivation. Functional connectivity analyses showed that the regions affected by sleep disorders were primarily connected with other areas involved in emotional regulation and self-referential thought, while the thalamic changes related to sleep deprivation connected to areas supporting attention, action planning, and sensory processing. This suggests that while both conditions impact brain function, they do so in different ways.
“Our study shows that chronic sleep disorders and short-term sleep deprivation affect different brain regions, suggesting distinct underlying mechanisms,” Reimann told PsyPost. “Chronic disorders consistently impact areas involved in emotion and memory – like the sgACC, amygdala, and hippocampus – helping to explain shared symptoms such as fatigue, mood changes, and memory issues. In contrast, short-term sleep loss is linked to the right thalamus, aligning with acute effects like impaired focus and physical discomfort.”
Complementary analyses provided additional support for these findings. The abnormalities in the subgenual anterior cingulate cortex and the right amygdala and hippocampus were seen across several types of sleep disorders, especially insomnia and obstructive sleep apnea. Meanwhile, changes in the thalamus were consistently observed across studies of both total and partial sleep deprivation. The findings related to the thalamus were particularly robust and remained stable even when accounting for potential publication bias.
“One of the most surprising aspects was the clear neurobiological separation between chronic sleep disorders and short-term sleep deprivation,” Reimann said. “Despite overlapping symptoms, the brain regions affected showed no anatomical overlap. This suggests that while the experiences may feel similar, the underlying mechanisms might be fundamentally different – an important insight for both diagnostics and treatment strategies.”
But the study, like all research, has limitations.
“While a meta-analysis is able to generate a robust result representing the convergent results across the literature, this comes with drawbacks or limitations, such as it cannot represent the entire neuroimaging literature, as there are exclusion criteria,” Reimann noted. “Some sleep disorders – like insomnia disorder and obstructive sleep apnea – were overrepresented, while others – like periodic limb movement disorder or congenital central hypoventilation syndrome – were underrepresented, which might affect how broadly the findings apply.”
“Additionally, the included studies are quite heterogenous, in sleep deprivation protocols, differences in whether participants were receiving treatment and how long they had been experiencing the disorder. Lastly, based on this analysis we cannot directly say in which way the regions are related to the disorders, whether it is the symptomatology or aetiology.”
The researchers emphasize that future studies should aim to examine how treatment for sleep disorders might influence the brain abnormalities identified here. It will also be important to investigate whether the observed brain changes are causes of sleep disturbance or consequences of it. In addition, better understanding the relationship between specific symptoms—such as fatigue, mood swings, or memory problems—and changes in brain regions like the amygdala and thalamus could help tailor new treatments.
“Our long-term goal is to better understand the neurobiological foundations of sleep disorders – both what different disorders have in common and how they differ from short-term sleep deprivation,” Reimann explained. “We aim to explore how specific brain regions and networks, such as the amygdala, hippocampus, and sgACC, relate to daytime dysfunction and whether these abnormalities reflect symptoms or underlying causes. This knowledge could pave the way for more targeted therapies, such as cognitive behavioral therapy (CBT), emotion-focused interventions, or neuromodulation techniques like transcranial magnetic stimulation (tMCS) that specifically address the affected brain regions.”
The study, “Distinct Convergent Brain Alterations in Sleep Disorders and Sleep Deprivation: A Meta-Analysis,” was authored by Gerion M. Reimann, Alireza Hoseini, Mihrican Koçak, Melissa Beste, Vincent Küppers, Ivana Rosenzweig, David Elmenhorst, Gabriel Natan Pires, Angela R. Laird, Peter T. Fox, Kai Spiegelhalder, Kathrin Reetz, Simon B. Eickhoff, Veronika I. Müller, and Masoud Tahmasian.
