Alcohol use and cognition: Processing speed and subjective executive function deficits across the spectrum of drinking behaviours

Previous research has demonstrated that multiple cognitive functions are impaired in alcohol use disorders, including executive functions and processing speed. Recovery of function may be possible, though to what extent is unclear. In non-dependent hazardous drinkers, executive function research is inconsistent (possibly due to a neurocompensatory mechanism of increased effort), as is processing speed literature. Self-report methods may provide a unique insight into executive functioning within different alcohol contexts, while differences in processing speed measurement may account for discrepancies. The purpose of this thesis was to investigate the relationship between alcohol use and cognitive function, in different contexts. A systematic review examined longitudinal recoverability of cognitive function during abstinence in individuals with an alcohol use disorder, followed by a series of studies that assessed subjective executive function and vibrotactile reaction time in a range of dependent and non-dependent drinkers. Overall, the results showed that 1) cognitive function in several areas can recover in individuals with an alcohol use disorder who maintain abstinence, 2) hazardous drinkers experience poorer subjective executive function, but 3) perform faster during choice reaction time, and 4) impaired choice reaction time is demonstrated during early abstinence in dependent drinkers compared to controls, as is worsening mental fatigue, specifically in outpatients. These results have implications for health providers and policymakers, as hazardous drinkers are subject to alcohol harms despite not being a clinically prioritised group, while outpatients, despite typically fewer complex needs, are experiencing potentially harmful effects of cognitive exertion, so may need more support within their treatment pathway