Objective: Alcoholism ultimately leads to impairment of memory and other cognitive functions. This can interfere with treatment, if cognitively impaired alcohol-dependent individuals have difficulties recalling and implementing skills acquired during therapy. We investigate if alcohol-dependent individuals without clinically apparent withdrawal symptoms may still be impaired in higher-order cognitive functions.
Methods: Thirty-four alcohol-dependent patients and 20 matched healthy controls were tested with the Verbal Learning and Memory Test which includes seven measurement points. The test comprises free recall, free recall after distraction and after 30 minute delay, and a word recognition task. Testing was performed between day seven and day 10 after the beginning of abstinence, when clinical withdrawal symptoms had ceased.
Results: Compared to healthy controls, alcohol-dependent patients performed worse in free recall after delay, but not in word recognition. Healthy controls showed a more linear progression of improvement in verbal memory performance. Overall, alcohol-dependent individuals showed reduced verbal learning efficiency. The extent of impaired recall after distraction was positively associated (one-tailed test) with history of delirium (r=0.34, p=0.04), seizures (r=0.46, p=0.01), and years since diagnosis for alcohol dependency (r=0.39, p=0.01).
Conclusions: Our results provide evidence that unmedicated alcohol-dependent patients without obvious withdrawal symptoms had impaired verbal recall, but normal recognition performance, at seven to 10 days after onset of abstinence. This deficit may deteriorate treatment outcomes due to poorer implementation of skills newly-learned during this time period.