Risk of psychosis following mild traumatic brain injury: a systematic review and meta-analysis

Mild traumatic brain injury (mTBI), commonly known as concussion, has historically been regarded as a transient and benign condition. However, recent studies suggest it may increase the risk of long-term psychiatric outcomes, including psychosis. This study aimed to systematically review and meta-analyze the association between mTBI and subsequent risk of psychosis.

A comprehensive search of PubMed, PsycINFO, and Google Scholar was conducted through June 2025. Studies were eligible if they included individuals with a history of mTBI, a non-TBI control group, and reported psychosis-related outcomes with estimable risk measures. Random-effects meta-analysis was performed using the metafor package in R. Risk of bias and publication bias were assessed, and meta-regression was conducted to explore moderators such as adjustment status and effect size type.

Seven studies comprising pediatric and adult populations were included. The pooled risk ratio (RR) for psychosis following mTBI was 1.57 (95% CI: 1.28-1.91, p < 0.001), indicating a statistically significant association. The 95% prediction interval (1.03-2.38) suggests generalizability across future studies. No significant publication bias was detected (Egger's test p = 0.10). Meta-regression found no difference between adjusted and unadjusted estimates (p = 0.802). Sensitivity analyses confirmed the robustness of the findings.

mTBI is associated with a moderate but statistically significant increase in the risk of psychosis. Given the prevalence of mTBI in the general population, these findings highlight the need for long-term psychiatric monitoring and preventive strategies, particularly in youth and high-risk individuals.