Pain Catastrophizing and Limiting Behavior Mediate the Association Between Anxiety and Postconcussion Symptoms.

Background: Despite growing evidence that anxiety is critical in the development and maintenance of postconcussion symptoms after mild traumatic brain injury (mTBI), little is known about potential mechanisms through which anxiety may affect these symptoms.

Objective: To test the strength and reliability of cognitive (pain catastrophizing) and behavioral (limiting behaviors) pathways mediating the relationship between anxiety and postconcussion symptoms among patients with mTBI.

Method: Patients with mTBI (N = 57) completed self-report measures of anxiety, postconcussion symptoms, pain catastrophizing, and limiting behavior. After preliminary simple-mediation models (for pain catastrophizing and limiting behavior separately), we ran a multiple-mediation model (pathways modeled simultaneously). Bootstrapping with 10,000 resampling iterations assessed mediation reliability.

Results: In preliminary simple mediation models, both pain catastrophizing (β = 0.24, 95% confidence interval [CI] = 0.03-0.44, P = 0.02) and limiting behaviors (β = 0.14, 95% CI = 0.03-0.26, P = 0.01) partially mediated the relationship between anxiety and postconcussion symptoms. In the multiple mediation model, pain catastrophizing was a less reliable but numerically stronger mediator (β = 0.19, 95% CI = -0.01 to 0.38; P = 0.05) and explained more variance in postconcussion symptoms (R = 0.41) than limiting behavior (β = 0.10, 95% CI = 0.02-0.21, P = 0.03; R = 0.22), although mediators did not significantly differ in strength (β = 0.08, 95% CI = -0.16 to 0.32; P = 0.49). Results provide novel evidence for the role of pain catastrophizing and limiting behaviors in explaining the association between anxiety and postconcussion symptoms. Addressing both factors may improve the recovery trajectory of individuals with mTBI. Emphasizing limiting behavior may yield more consistent and reliable effects.

Conclusion: Results support developing interventions to directly target anxiety, for pain catastrophizing, and for activity engagement despite symptoms, to decrease symptom severity among patients with mTBI.