Introduction / Rationale: Generalized anxiety disorder (GAD) is a prevalent mental health condition characterized by excessive and persistent worry. It significantly impacts cognitive function, particularly response inhibition, yet the underlying neural mechanisms remain unclear. The prefrontal cortex (PFC) plays a critical role in both inhibitory control and anxiety regulation, but its involvement in GAD is complex and task-dependent. Further research is needed to elucidate these mechanisms.
Objectives: This study investigated PFC activity during response inhibition in individuals with GAD compared to healthy controls.
Methods / Approach: Functional near-infrared spectroscopy (fNIRS) was used to measure hemodynamic responses in the bihemispheric PFC of 19 GAD patients and 28 healthy controls before and during a Go/No-Go task, where participants responded to target stimuli with a key press and withheld responses to non-target stimuli. Between-group differences in PFC activation were analyzed with independent t-tests.
Results / Practice Implications: Compared to healthy controls, patients with GAD exhibited significantly lower hemoglobin concentration across the bihemispheric PFC during both baseline and task conditions, with pronounced hypoactivity in the dorsolateral PFC, dorsomedial PFC, and right ventromedial PFC (p = 0.015–0.050).
Conclusion / Contribution to the occupational therapy profession: Our results revealed consistent hypoactivity across both baseline and task conditions, suggesting not only chronic under-engagement of the PFC in the absence of specific tasks but also a dysfunctional neural circuitry that hinders anxiety regulation and response inhibition. These results highlight distinct neural processing abnormalities in GAD, emphasizing the role of PFC dysfunction in its pathology. They also underscore the need for targeted interventions to enhance cognitive control and emotional regulation in individuals with GAD.