| Studies examining the effects of heavy alcohol use on memory functioning have shown inconsistencies in the severity of potential deficits and whether verbal or non-verbal memory is most affected. Additionally, the role of attention and learning in memory deficits has remained unclear. The objective of the current meta-analyses was to analyze the heterogeneity in memory effect sizes reported between abstinent alcoholics and healthy controls to better understand the factors contributing to memory deficits. A comprehensive search was conducted utilizing multiple databases to retrieve primary studies of memory and other neuropsychological functioning in abstinent alcoholics. Ninety-two studies were included producing 100 comparisons with 7,197 participants in total. Neuropsychological measures were analyzed on a test-level and composite-level basis by statistically combining reported scores into categories. This was done to test laterality of deficits and evaluate relationships between attention, learning, and memory. Subgroup analyses and meta-regression were used. Results indicated that both verbal and non-verbal memory are affected by long-term heavy drinking. However, even small non-significant discrepancies in matching for education may be inflating verbal effect sizes. Future research should focus on more precise matching, especially on educational variables. Additionally, results indicated that memory deficits are most likely the result of poor attention and impaired learning due to heavy alcohol use. These memory deficits may increase over the first year of abstinence. Therefore, it is essential for both researchers and clinicians to account for the role of attention and learning in memory complaints of abstinent alcoholics. |
