Influence of Alcohol and Acetaldehyde on Cognitive Function: Findings from An Alcohol Clamp Study in Healthy Young Adults.

AIMS To investigate the acute effects of intravenous alcohol and its metabolite acetaldehyde on cognitive function in healthy individuals. DESIGN Experimental pretest-posttest design. SETTING Kurihama Medical and Addiction Center, Japan. PARTICIPANTS 298 healthy Japanese people aged 20-24 years. MEASUREMENTS Participants underwent an intravenous alcohol infusion with a target blood alcohol concentration (BAC) of 0.50 mg/mL for 180 min. Participants completed the continuous performance test (CPT) for sustained attention, the paced auditory serial addition test (PASAT) for working memory, and the reaction time test (RTT) for speed/accuracy, along with the blood test for BAC and blood acetaldehyde concentration (BAAC) at baseline, 60, and 180 min. FINDINGS While the target BAC was maintained during the infusion, BAAC peaked at 30 min and then gradually declined (η2 =0.18, p<0.01). The CPT scores worsened, and the changes between 0-60 min were correlated with BAAC (correct detection, η2 =0.09, p<0.01; r=-0.34, p<0.01; omission errors, η2 =0.08, p<0.01; r=0.34, p<0.01). PASAT scores improved through 180 min, while the changes between 0-60 min were negatively correlated with BAAC (task one, η2 =0.02, p<0.01; r=-0.25, p<0.01; task two, η2 =0.03, p<0.01; r=-0.28, p<0.01). Although RTTs worsened, they were not associated with BAC or BAAC. None of these comparisons maintained the time effect after controlling for body height. CONCLUSIONS Acetaldehyde exposure following acute intravenous alcohol appears to have a negative impact on sustained attention and working memory, while there seems to be only a minor effect of moderate alcohol concentration on speed and accuracy.