DLPFC activation and inhibitory control serve as neurocognitive pathways linking anxiety and sleep quality, with serial mediation analysis showing that dorsolateral PFC activation and inhibitory performance sequentially mediated the relationship between anxiety and sleep quality.
Key Findings
Results
Patients with anxiety disorders exhibited poorer sleep quality, slower response time, lower inhibitory accuracy, and reduced PFC activation compared to healthy controls.
All group differences were statistically significant at p < 0.001
Sample included 91 patients with anxiety disorders and 90 age- and sex-matched healthy controls
Measures included the Pittsburgh Sleep Quality Index (PSQI), color-word Stroop task performance, and fNIRS-measured prefrontal activation
No group differences were found in task-related functional connectivity (p = 0.94)
Results
Anxiety was positively associated with poorer sleep quality.
Correlation coefficient r = 0.76, p < 0.001
Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI)
Anxiety was measured using Zung's Self-rating Anxiety Scale (SAS)
This was one of the strongest correlations observed in the study
Results
Anxiety was positively associated with impaired inhibitory performance.
Correlation coefficient r = 0.46, p < 0.001
Inhibitory performance was assessed using the color-word Stroop task
Higher anxiety scores corresponded to slower response times and lower inhibitory accuracy
Results
Anxiety was negatively associated with prefrontal cortex activation during the Stroop task.
Correlation range r = -0.6 to -0.2, p < 0.05
PFC activation was measured using functional near-infrared spectroscopy (fNIRS)
Higher anxiety levels corresponded to reduced PFC activation during inhibitory task performance
Results
Poor sleep quality was negatively associated with PFC activation.
Correlation range r = -0.59 to -0.19, p < 0.05
Poor sleep quality was also positively associated with inhibitory deficits (r = 0.5, p < 0.001)
These associations were observed across the full sample of 181 participants
Results
Dorsolateral PFC (DLPFC) activation and inhibitory performance sequentially mediated the relationship between anxiety and sleep quality.
Serial mediation analysis was used to test the sequential pathway
The mediation pathway ran from anxiety → DLPFC activation → inhibitory performance → sleep quality
This suggests DLPFC activation and inhibitory control are neurocognitive pathways linking anxiety and sleep quality
The mediation was specifically identified in the DLPFC region rather than PFC broadly
Methods
The study used functional near-infrared spectroscopy (fNIRS) to measure prefrontal cortex activation during a color-word Stroop task in a clinical sample.
Total sample of 181 participants: 91 anxiety disorder patients and 90 healthy controls matched for age and sex
Participants completed Zung's Self-rating Anxiety Scale (SAS), the Pittsburgh Sleep Quality Index (PSQI), and the color-word Stroop task
fNIRS was used to capture task-related PFC activation and functional connectivity
Both task performance metrics (response time and accuracy) and neural activation were measured
What This Means
This research suggests that the well-known link between anxiety and poor sleep is not direct, but rather works through the brain and cognitive functioning. People with anxiety disorders showed worse sleep, slower and less accurate thinking under cognitive challenge, and less activity in the prefrontal cortex (the brain region involved in self-control and decision-making) compared to healthy individuals. The study measured brain activity using a non-invasive light-based technique called fNIRS while participants performed a color-word matching task designed to test mental control and inhibition.
The key finding is that reduced activity in a specific part of the prefrontal cortex called the dorsolateral prefrontal cortex (DLPFC), combined with poorer ability to suppress distracting information (inhibitory control), together explain much of why anxious people sleep poorly. In statistical terms, these two factors acted as 'serial mediators' — anxiety first reduces DLPFC activity, which then impairs inhibitory control, which in turn leads to worse sleep quality.
This research suggests that treatments aimed at strengthening inhibitory control and prefrontal brain function — such as certain cognitive training programs — might help improve sleep in people with anxiety disorders, rather than targeting sleep directly. The findings provide a neurocognitive explanation for a common clinical observation and could inform the development of more targeted interventions for people who experience both anxiety and sleep problems.
Lin B, Wang D, Schroevers M, Huang Y, Chong Z, Liu X, et al.. (2026). Prefrontal activation and inhibitory performance in the association between anxiety and sleep quality: An fNIRS investigation.. Journal of affective disorders. https://doi.org/10.1016/j.jad.2026.121245