Predictors of cognitive functioning in presentations to a community-based specialist addiction neuropsychology service

Abstract

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.

Maybe It's Not the Meth: Considering Biopsychosocial Contributors to Cognitive Impairment in Methamphetamine Polydrug Use

“…In these contexts, it is often not possible to attribute causality or identify MA use as a specific etiology, as many of these other demographic, neurodevelopmental, medical, psychiatric or polysubstance use factors are well known to significantly influence cognitive functioning. Importantly, these experiences of cognitive difficulty were sufficient to warrant formal neuropsychological investigation and consistent with prior work, a range of modifiable and non-modifiable risk factors for cognitive decline were present, such as heightened emotional distress, that may account for these difficulties (19). These factors have important implications for the interpretation of past and future research work and also for clinicians working with these cohorts as they must be well attuned to the presence of these factors and able to ensure they are well managed through appropriate referral and treatment.…”

“…Similarly, premorbid characteristics such as pre-existing neurodevelopmental disabilities were also common and could account for some aspects of cognitive difficulty in these cohorts ( 13 , 19 , 54 ). It was notable that 15% of the MA-polydrug cohort had diagnoses of ADHD, which is higher than rates in the adult population more broadly and in keeping with previous literature that has suggested rates of ADHD are between 2 and 6 times higher in MA users ( 55 , 56 ).…”

“…While these findings are consistent with prior research in substance using cohorts ( 8 , 9 ), with some associations between emotional distress and intellectual functioning being demonstrated ( 52 ), the significant impact of emotional distress upon cognitive functioning is often not appropriately considered. Such symptoms are critical to consider as the presence of mental health and psychiatric comorbidities represent potentially modifiable risk factors for cognitive impairment ( 15 – 17 , 19 , 53 ). For example, in a recent study of the biopsychosocial predictors of neuropsychological functioning in substance users attending for neuropsychological assessment, emotional distress was consistently shown to have an independent contribution to test performances on several cognitive domains including information processing speed, working memory and divided attention ( 19 ).…”

“…Such symptoms are critical to consider as the presence of mental health and psychiatric comorbidities represent potentially modifiable risk factors for cognitive impairment ( 15 – 17 , 19 , 53 ). For example, in a recent study of the biopsychosocial predictors of neuropsychological functioning in substance users attending for neuropsychological assessment, emotional distress was consistently shown to have an independent contribution to test performances on several cognitive domains including information processing speed, working memory and divided attention ( 19 ).…”

“…Similarly, emotional distress and psychiatric conditions have well established links with reduced cognitive functioning (15)(16)(17) and these conditions are frequently observed in substance using groups (18). In a recent study exploring the biopsychosocial predictors of neuropsychological functioning in a sample of treatment seeking substance users with cognitive concerns, factors including basic demographics, prescribed sedating medications, emotional distress, and formal diagnoses of acquired brain injury and neurodevelopmental conditions were found to have independent contributions to aspects of neuropsychological functioning (19). Despite the known impacts of broader contextual factors upon cognition in polysubstance groups more generally, there nonetheless continues to be a limited appreciation or recognition of the impact of pre-existing, comorbid, and/or modifiable risk factors for cognitive impairment in heavy MA-users.…”