A meta-analysis of 29 fMRI studies involving 2,579 participants found that insomnia disorder is associated with three key brain network disruptions: salience network hyperactivity, default mode network hypoactivity, and executive circuit dysfunction, with right inferior frontal gyrus hypoactivation representing a consistent abnormality across both resting and task states.
- Analysis of 29 brain imaging studies (1,305 insomnia patients, 1,274 healthy controls) identified three major brain network disruptions in insomnia
- Right inferior frontal gyrus hypoactivation was the only consistent abnormality found across both resting and task-based brain states
- Brain alterations were linked to genes involved in synaptic signaling and metabolic pathways
How this compares to prior research
Previous neuroimaging studies of insomnia disorder have shown considerable heterogeneity in findings, making it difficult to identify consistent brain alterations. It remained unclear whether functional brain changes in insomnia were consistent across different brain states (resting versus performing tasks). This meta-analysis addressed these gaps by systematically analyzing 29 studies to identify both state-common and state-specific neural signatures of insomnia disorder.
Insomnia prevalence among global population, 1990–1999
Key findings
- Three convergent network disruptions were identified: salience network hyperactivity, default mode network hypoactivity, and executive circuit dysfunction
- Right inferior frontal gyrus hypoactivation was the sole convergent abnormality across both resting and task-based brain states, linked to inhibitory control, working memory, and attention
- Functional brain alterations were significantly associated with synaptic signaling genes (positive loading) and carbohydrate metabolism and mitochondrial function genes (negative loading)
What this means in practice
- Discuss executive function difficulties with your doctor if you have insomnia, as the study links sleep problems to brain regions controlling attention and impulse control
- Consider that insomnia involves measurable brain changes, not just subjective sleep complaints, which may help validate treatment approaches
- Note that metabolic and synaptic pathways are implicated, suggesting lifestyle factors affecting brain energy metabolism may influence insomnia severity
Frequently asked questions
What brain regions are affected in people with insomnia?
The study found disruptions in three major brain networks: the salience network (overactive), default mode network (underactive), and executive circuits. The right inferior frontal gyrus showed consistent underactivity across different brain states.
How many studies were included in this analysis?
The meta-analysis included 29 whole-brain fMRI studies with 2,579 total participants: 1,305 people with insomnia disorder and 1,274 healthy controls. Twenty-two studies examined resting-state brain activity and seven examined task-based activity.
What genes are linked to insomnia-related brain changes?
The brain alterations in insomnia were associated with genes involved in synaptic signaling (positively correlated) and genes related to carbohydrate metabolism and mitochondrial function (negatively correlated), suggesting both communication and energy metabolism disruptions.
Key terms explained
salience network
A brain network that detects and filters important stimuli, helping direct attention to relevant information in the environment.
default mode network
A brain network active during rest and internal thought processes like daydreaming, self-reflection, and memory retrieval.
right inferior frontal gyrus
A brain region involved in inhibitory control, working memory, and attention, located in the frontal lobe\’s lower right side.
Source: Neural-molecular signatures of insomnia: Insights from signed differential mapping and gene expression analysis. · DOI: doi: 10.1016/j.neuroimage.2026.121926