Prefrontal activation and inhibitory performance in the association between anxiety and sleep quality: An fNIRS...

Anxiety and sleep disturbances are closely linked, yet their underlying neural and cognitive associations remain insufficiently understood. This study examined the roles of prefrontal cortex (PFC) activation and inhibitory performance in this relationship within a clinical context.

A total of 181 participants, including 91 patients with anxiety disorders and 90 age- and sex-matched healthy controls (HCs), completed Zung's Self-rating Anxiety Scale (SAS), the Pittsburgh Sleep Quality Index (PSQI), and the color-word Stroop task. Prefrontal activation during the task was measured using functional near-infrared spectroscopy (fNIRS).

Compared to HCs, patients with anxiety disorders exhibited poorer sleep quality, slower response time, lower inhibitory accuracy, and reduced PFC activation (all p < 0.001). No group differences were found in task-related functional connectivity (p = 0.94). Anxiety was positively associated with poorer sleep quality (r = 0.76, p < 0.001) and impaired inhibitory performance (r = 0.46, p < 0.001), and negatively associated with PFC activation (r = -0.6 to -0.2, p < 0.05). Poor sleep quality was positively associated with inhibitory deficits (r = 0.5, p < 0.001) and negatively associated with PFC activation (r = -0.59 to -0.19, p < 0.05). Serial mediation analysis showed that dorsolateral PFC (DLPFC) activation and inhibitory performance sequentially mediated the relationship between anxiety and sleep quality.

Our findings suggest that DLPFC activation and inhibitory control serve as neurocognitive pathways linking anxiety and sleep quality. Interventions enhancing inhibitory function may thus improve sleep quality and overall functioning in individuals with anxiety disorders.