Demographic-Dependent Risk of Developing Novel Psychiatric Disorders Following Concussion

Importance: Current guidelines for patients who have experienced a concussion or mild traumatic brain injury (mTBI) often focus on conservative care and observation. However, mTBI may increase the risk of novel psychiatric disorders (NPDs) within 180 days, and long-term management of mTBI should include psychiatric evaluation for high-risk populations. Objective: To investigate the association between NPDs and mTBI. Design, Setting, and Participants: This retrospective cohort analysis was conducted using 8-years of the National Readmission Database. All individuals who were admitted for a diagnosis of concussion and were readmitted within 180 days following discharge were queried; patients without complete follow-up were excluded. This cohort was then subdivided based on age (by quartile), sex, and whether the individual experienced loss of consciousness (LOC) to control for demographic-dependent confounding. Analysis was conducted for the total and subdivided cohorts, and the results were used to develop a binary decision tree to provide recommendations for high-risk patient populations. Main Outcomes and Measures: Development of NPDs within 180 days, including: depression, anxiety, suicidal ideation, and homicidal ideation. All psychiatric disorders were identified using International Classification of Diseases, Ninth Revision (ICD-9) and International Classification of Diseases, Tenth Revision (ICD-10) codes. Results: Analysis was conducted with a cohort of 12,080 patients (mean age: 59.5±21.6; 49.8% female) who were admitted initially for concussion. Males and females with LOC had higher rates of depression in all age quartiles within 180 days (p<0.05 for all). Females in the first two age quartiles with LOC also had an increased rate of suicidal ideation (p<0.01 for all), and those older than 25 years had increased rates of anxiety upon readmission within 180 days (p<0.005 for all). Males younger than 75 with LOC and significantly increased rates of suicidal ideation (p<0.002 for all) and those in the second and fourth quartile for age had increased rates of anxiety at readmission (p<0.05 for all). Males in the first, second, and fourth age quartile without LOC had significantly increased rates of depression (p<0.005 for all), with men in the second quartile also at higher risk of developing anxiety at readmission (p<0.05). Females without LOC showed the fewest number of NPDs within 180 days, with those below 25 years of age having significantly higher rates of anxiety (p<0.05) and those above 75 years of age having significantly higher rates of suicidal ideation at readmission (p<0.05). Conclusions and Relevance: Our findings suggest that concussion may be associated with an increased rate of NPDs within the first 6 months following discharge. We use this data to develop recommendations for psychiatric screening of high-risk patient populations. Other factors may contribute towards the development of NPDs, and further research is necessary to understand the associations between mild traumatic brain injury and psychiatric illness. Funding Statement: There are no disclosures of funding for this study. Declaration of Interests: Chan: receives non-study related research support from Orthofix, Inc.