Prevalence and moderators of apathy after traumatic brain injury: A systematic review and meta-analysis

Apathy is a recognized neuropsychiatric syndrome in individuals with traumatic brain injury (TBI) with far-reaching consequences, including reduced independence, meaningful activities and quality of life. However, previous studies have reported variable prevalence rates and no meta-analysis has synthesized prevalence findings and identified moderators of apathy in clinical populations. We conducted a pre-registered meta-analysis (PROSPERO CRD42024552306), searching three databases (MEDLINE, EMBASE, and APA PsycInfo) for primary studies assessing apathy in individuals with TBI. 18 studies met inclusion criteria, and data were extracted for meta-analysis to estimate the pooled prevalence of apathy. Subgroup analyses and meta-regressions explored the influence of potential moderating factors including demographic characteristics, injury-related factors, and methods of apathy assessment. The meta-analysis found the prevalence of apathy following TBI to be 37.6% [95% CI 28.5-47.2%]. Key moderators included cause of injury, TBI severity, sex and population type. Specifically, transport accidents were associated with higher apathy prevalence, while mild TBI, male sex, and veteran status were associated with lower apathy prevalence. Apathy is a prevalent and significant symptom following TBI, affecting over one-third of individuals in the reviewed studies. These findings highlight the need for increased clinical focus on apathy as an important aspect of TBI recovery.