A role for cognitive rehabilitation in increasing the effectiveness of treatment for alcohol use disorders

Abstract

Neurocognitive impairments are prevalent in persons seeking treatment for alcohol use disorders (AUDs). These impairments and their physical, social, psychological and occupational consequences vary in severity across persons, much like those resulting from traumatic brain injury; however, due to their slower course of onset, alcohol-related cognitive impairments are often overlooked both within and outside of the treatment setting. Evidence suggests that cognitive impairments can impede treatment goals through their effects on treatment processes. Although some recovery of alcohol-related cognitive impairments often occurs after cessation of drinking (time-dependent recovery), the rate and extent of recovery is variable across cognitive domains and individuals. Following a long hiatus in scientific interest, a new generation of research aims to facilitate treatment process and improve AUD treatment outcomes by directly promoting cognitive recovery (experience-dependent recovery). This review updates knowledge about the nature and course of cognitive and brain impairments associated with AUD, including cognitive effects of adolescent AUD. We summarize current evidence for indirect and moderating relationships of cognitive impairment to treatment outcome, and discuss how advances in conceptual frameworks of brain-behavior relationships are fueling the development of novel AUD interventions that include techniques for cognitive remediation. Emerging evidence suggests that such interventions can be effective in promoting cognitive recovery in persons with AUD and other substance use disorders, and potentially increasing the efficacy of AUD treatments. Finally, translational approaches based on cognitive science, neurophysiology, and neuroscience research are considered as promising future directions for effective treatment development that includes cognitive rehabilitation.

Figures

Fig. 1. Brain structure changes associated with chronic heavy alcohol use

Early studies on the brain of alcohol dependent individuals consistently demonstrated decreased brain volume and ventricular and sulcal enlargement, although changes did not appear uniform across all brain structures. Current knowledge based on a variety of neuroimaging techniques suggests that limbic structures (amygdala = red, hippocampus = orange, temporal lobe gyri = green, cingulate cortex = turquoise), frontal cortical structures (prefrontal cortex and frontal cortex in shades of blue), and the cerebellum (dark purple) are especially vulnerable to chronic use. The extensive bidirectional connectivity between these structures also appears prone to disruption. Brain abnormalities may be fully or partially stabilized or reversed with extended abstinence. Current research is specifying region-specific recovery trajectories and risk for persistent versus reversible abnormalities.

Fig. 2. Improvement in cognitive functioning across the first year post-treatment entry in substance dependent individuals (n=197)

Panel (a) shows that the steepest increments in recovery in all domains occurred between treatment entry and the 6-week follow-up. Mean performance in the memory domain continued to significantly improve between the 6- and 26-week follow-ups. These improvements occurred after acute withdrawal and in the absence of intervention aimed at cognitive remediation. They did not reflect practice effects due to repeated exposure to the test materials (data not shown). Panels (b) and (c) show standard deviation error bars for executive and memory latent means. Note the considerable variability in latent ability across individuals at each follow up: individuals variously exhibited low or high stable levels of functioning across time, showed small, moderate or large increases in abilities, and even in some cases showed decreases in ability over time. Within-person improvement across 1 year following treatment may thus reflect improvements noted in cross-sectional studies of groups studied at different time points following cessation of drinking, or vary dramatically from this pattern.