Verbal memory performance in alcohol-cocaine versus alcohol use disorder: selective impairment in delayed free recall

Abstract

Aim: To examine whether individuals with alcohol-cocaine use disorder exhibit selective impairments in self-initiated verbal retrieval compared to individuals with alcohol use disorder alone.

Methods: Sixty outpatients meeting Diagnostic and Statistical Manual of Mental Disorders-Five Edition (DSM-5) criteria for Alcohol Use Disorder were classified into alcohol-only (n = 29) and alcohol-cocaine (n = 31) groups using the Structured Clinical Interview for DSM-5. Narrative delayed free recall was assessed in all participants (n = 60), while word-list learning and visual memory measures were available for 51 participants. Group differences were examined using general linear models controlling for age, estimated intellectual quotient, and benzodiazepine use. Urine toxicology screening was conducted prior to each assessment session to ensure recent abstinence from substances.

Results: After adjustment, the alcohol-cocaine group demonstrated significantly lower performance in delayed free recall of narrative material compared to the alcohol-only group (P = .010, η2p = .114). A similar but non-significant trend was observed for delayed word-list recall (P = .054). No group differences were found in cued recall, recognition performance, or visual memory measures.

Conclusions: Alcohol-cocaine use disorder was associated with reduced efficiency in self-initiated verbal retrieval, while externally supported recall and visual memory remained relatively preserved. These findings suggest a selective impairment in strategic retrieval processes rather than a generalized memory deficit.

Keywords: alcohol use disorder; cocaine; executive processes; neuropsychology; verbal memory.