Network analysis of anxiety and depressive symptoms one year after traumatic brain injury.

We used network analysis to explore interrelationships between anxiety and depressive symptoms after traumatic brain injury (TBI). At one year post-injury, 882 adult civilians who received inpatient rehabilitation for moderate-severe TBI self-reported anxiety and depressive symptoms (Hospital Anxiety and Depression Scale). The severity of TBI was characterized acutely by the duration of post-traumatic amnesia (PTA), and TBI-related functional disability was rated by an examiner at one year post-injury using a structured interview (Glasgow Outcome Scale - Extended). We estimated two cross-sectional, partial correlation networks. In the first network, anxiety and depressive symptoms were densely interconnected yet formed three distinct, data-driven communities: Hyperarousal, Depression, and General Distress. Worrying thoughts and having difficulty relaxing were amongst the most central symptoms, showing strong connections with other symptoms within and between communities. In the second network, TBI severity was directly negatively associated with hyperarousal symptoms but indirectly positively associated with depressive symptoms via greater functional disability. The results highlight the potential utility of simultaneous, transdiagnostic assessment and treatment of anxiety and depressive symptoms after moderate-severe TBI. Worrying thoughts, having difficulty relaxing, and the experience of disability may be important targets for treatment, although future studies examining symptom dynamics within individuals and over time are required.