Decoding TBI Complexity: A Person-Centred Approach to Exploring TBI in Substance Use Populations and Its Impact on Social Cognition

<p><strong>Traumatic brain injuries (TBIs) are often referred to as the silent epidemic (Rusnak, 2013). Longitudinal studies have established apparent vulnerabilities associated with TBIs, demonstrating its heightened impact over time (Anderson et al., 2000; A. Crawford et al., 2020). However, the impact of TBIs are complex as outcomes may vary for individuals. These complexities arise from bi-directional interactions with confounding variables such as substance use and social cognition, which can exacerbate negative outcomes (Chan et al., 2022; McDonald, 2013). Existing research often examines these factors in isolation, neglecting to consider the interplay of these factors that could potentially create a ‘triple jeopardy’ effect. The majority of TBI literature takes a variable-based approach; however, a variable-based approach cannot account for TBIs' multifaceted nature. A person-oriented approach allows to identify distinct subgroups within a population, enabling better prediction of individual outcomes (Bergman et al., 2002). Therefore, this study aimed to categorise TBIs based on their patterns (i.e., age of onset and frequency) and investigate the relationships between demographics, substance use, and TBI characteristics, outcomes, and social cognition deficits. This study examined a sample from a residential substance use program, grouping participants based on patterns of historical injuries, specifically the age of onset and frequency of TBIs. Notably, educational achievement, depression, and anxiety were significant factors within the age-of-onset category. These findings highlight the teenage brain's vulnerability, emphasising its short-term effects and long-term consequences.</strong></p><p>Demographic and substance use characteristics and outcome measures were examined to assess social cognition deficits. Results indicated that Māori and poly-substance users demonstrated poorer performance on the social cognition test. Māori participants struggling with identifying negative emotions and interpreting complex social inferences. These findings emphasise the need for culturally appropriate social cognition assessment tools. Additionally, polysubstance users performed worse on interpreting complex social inferences, highlighting the significant neurological impact of using multiple substances. This underscores the lack of literature and the numerous confounding variables influencing poly-substance research, such as usage patterns and frequency.</p>