B - 22 Self-Reported Traumatic Brain Injury and its Biopsychosocial Risk Factors in Siblings of Individuals with Neurodevelopmental Conditions

Abstract Objective Siblings of individuals with neurodevelopmental conditions (NDCs) are situated within a complex system of transdiagnostic risk and resilience factors for poor psychosocial, cognitive and behavioral outcomes. Many such factors experienced by NDC siblings overlap with risk for traumatic brain injury (TBI) and correlate with poorer recovery trajectories. Method With data from an online self-report survey, the present study used Bayesian analyses to characterize and compare TBI and biopsychosocial risk factors amongst 632 siblings (207 NDC, 425 controls; mean age 20.54 years, range 10–30, 78.48% female), and examine correlations between clinical, biological, and social determinant of health variables. Results NDC siblings had a higher self-reported lifetime history of TBI compared to controls (14.98% versus 6.35%), with most NDC siblings reporting more than one TBI, and at an earlier mean age. TBI history was associated with psychiatric diagnoses and subclinical NDC features, including hyperactivity and impulsivity, inattention, conduct problems, and autistic traits. Family and structural factors related to TBI included poorer parent–child relationship, NDC diagnoses of autism or fetal alcohol spectrum disorder, minority ethnicity and lower income. Conclusions Findings have important clinical and policy implications for health literacy, TBI education and screening, development of prevention and intervention strategies, and implementation of family support to target social and structural determinants of health impacting NDC sibling wellbeing.