Biopsychosocial and environmental factors play a major role in acute clinical presentation, recovery, and outcome of traumatic brain injury (TBI). As part of the 2024 National Institute of Neurological Disorders and Stroke (NINDS) TBI Classification and Nomenclature Initiative, the Psychosocial and Environmental Modifiers (PEM) Working Group was assembled to perform a narrative review and summary of expert opinions regarding how non-TBI factors influence the presenting features and outcomes of TBI and to make recommendations for incorporating these Modifiers into clinical care and research. With input from working group members and other interested parties, we summarize the membership, methods, and outcomes of the PEM Working Group activities. Modifiers were considered with the NINDS Social Determinants of Health Framework in mind and fall under three broad headings: individual-level variables (e.g., demographics, preinjury health, culture), injury-related variables (e.g., cause and context of injury, second insults), and community-/societal-level factors (e.g., family/community support, socioeconomic position, structural racism). Recommendations include steps to increase awareness of Modifiers in health care encounters, identify Modifier-related disparities in TBI-related care and outcomes, better understand the mechanisms by which Modifiers influence TBI-related clinical presentation and outcomes, and intervene to improve the health and well-being of persons exposed to TBI. These recommendations are intended to be a starting point that will evolve as knowledge grows and additional input is incorporated.
Keywords: CBI-M Model; blood-based biomarkers; classification; clinical assessment; neuroimaging; social determinants of health.