Objective The purpose of this study was to evaluate the development of clinically diagnosed anxiety or depression within one year following a major traumatic brain injury (MTBI).

Design A state-wide hospital system (Ochsner Health) retrospective cohort analysis.

Setting This study investigates the development of clinically diagnosed anxiety and/or depression within a set one-year time period following MTBI.

Participants 2,960 patients presenting to the Ochsner Health system between 2010 and 2020 with clinically diagnosed MTBI and developed a psychiatric condition (including all mental, behavioral and neurodevelopmental disorders). Patients had no psychiatric conditions prior to MTBI.

Outcome Measures Development of anxiety and/or depression, according to ICD-10 criteria.

Main Results Of the 2,960 MTBI patients, 90 (3.04%) developed diagnosed anxiety alone, 60 (2.02%) developed clinical depression alone, and 112 (3.78%) patients developed both anxiety and depression within one year of MTBI.

Conclusions Our findings provide further evidence of the development of psychiatric conditions within one year of MTBI.