Individuals with TBI who failed an on-road assessment significantly overestimated their driving ability. Impaired cognitive function was associated with reduced self-awareness of driving. These findings suggest impaired awareness of driving may need to be addressed as part of driver rehabilitation programs.

Introduction and AimsCognitive impairment is a common feature of individuals with substance‐use disorders. However, research tends to exclude highly complex clinical cases, limiting the generalisability of findings for ‘real‐world' populations. The objective of this study was to examine the complexities associated with addiction, substance use and cognitive impairment through the characterisation of client presentations to a newly established specialised addiction neuropsychology service.Design and MethodsRetrospective case file audit. Neuropsychological assessment reports for consenting clients over a 4‐year period were de‐identified and reviewed. Cognitive domains assessed included attention, processing speed, working memory, intellectual functioning, memory and executive functioning.ResultsOf the 200 case files examined, the majority were male clients, with 11 years or lower of education and a history of daily substance use, with 30% continuing to use daily. Seventy‐one percent had a formal mental health diagnosis and 41% had reported a history of trauma. The most prevalent cognitive impairments were observed in complex attention (50%) and memory (40%). New diagnoses were conveyed in 25% of cases, comprising acquired brain injury (16%) and neurodevelopmental disabilities (9%).Discussion and ConclusionsIt is common for clients with substance use histories referred to an addiction neuropsychology service to present with complex histories including psychosocial difficulties, comorbid mental health and medical issues and cognitive impairment. As such, careful diagnostic formulations are required when multiple factors may contribute to cognitive deficits. This study highlights the importance of a state‐wide specialist addiction neuropsychology service in supporting diagnostic clarification and informing relevant treatment approaches.

Introduction: Cognitive impairment is common in individuals presenting to alcohol and other drug (AOD) settings and the presence of biopsychosocial complexity and health inequities can complicate the experience of symptoms and access to treatment services. A challenge for neuropsychologists in these settings is to evaluate the likely individual contribution of these factors to cognition when providing an opinion regarding diagnoses such as acquired brain injury (ABI). This study therefore aimed to identify predictors of cognitive functioning in AOD clients attending for neuropsychological assessment. Methods: Clinical data from 200 clients with AOD histories who attended for assessment between 2014 and 2018 were analysed and a series of multiple regressions were conducted to explore predictors of cognitive impairment including demographic, diagnostic, substance use, medication, and mental health variables. Results: Regression modelling identified age, gender, years of education, age of first use, days of abstinence, sedative load, emotional distress and diagnoses of ABI and developmental disorders as contributing to aspects of neuropsychological functioning. Significant models were obtained for verbal intellectual functioning (Adj R2 = 0.19), nonverbal intellectual functioning (Adj R2 = 0.10), information processing speed (Adj R2 = 0.20), working memory (Adj R2 = 0.05), verbal recall (Adj R2 = 0.08), visual recall (Adj R2 = 0.22), divided attention (Adj R2 = 0.14), and cognitive inhibition (Adj R2 = 0.07). Conclusions: These findings highlight the importance of careful provision of diagnoses in clients with AOD histories who have high levels of unmet clinical needs. They demonstrate the interaction of premorbid and potentially modifiable comorbid factors such as emotional distress and prescription medication on cognition. Ensuring that modifiable risk factors for cognitive impairment are managed may reduce experiences of cognitive impairment and improve diagnostic clarity.

This exploratory study indicated that drivers with traumatic brain injury who failed on-road assessment demonstrated a heterogeneous pattern of impaired driving manoeuvres, characterised by skill deficits across both operational (e.g., basic car control and lane position) and tactical domains (e.g., following distance, gap selection, and observation) of driving. These preliminary findings can be used for implementation of future driving assessments and rehabilitation programs. Implications for rehabilitation Clinicians should be aware that the majority of individuals with traumatic brain injury were deemed fit to resume driving following formal on-road assessment, despite having moderate to very severe traumatic brain injuries. Drivers with traumatic brain injury who failed an on-road assessment demonstrated a heterogeneous pattern of impaired skills including errors with observation, speed regulation, gap selection, and vehicle control and accordingly had difficulty executing a diverse range of common driving manoeuvres. Comprehensive, formal on-road assessments, incorporating a range of skills, and manoeuvres, are needed to evaluate readiness to return to driving following traumatic brain injury. Individually tailored driver rehabilitation programs need to address these heterogeneous skill deficits to best support individuals to make a successful return to driving post-traumatic brain injury.