Introduction
Consumption of substances has been associated with cognitive impairment. The Mini Mental State Examination (MMSE) is an easy-to-apply screening tool used to assess cognitive functions.

Objectives
To evaluate the cognitive performance of individuals with alcohol (AUD) and/or crack cocaine use disorder (CUD) and polysubstance use using the MMSE and to investigate the impact of substance use profile and the moderation effect of educational level on MMSE performance.

Methods
Cross-sectional study with 508 adult male inpatients diagnosed with substance use disorders (245 with AUD, 85 with CUD, and 178 with polysubstance use). Cognitive performance was assessed using the MMSE scale (total and composite scores).

Results
Individuals with AUD had worse total MMSE scores and scored worse for all three MMSE components compared to individuals with polysubstance use (p < 0.001, oral/written language comprehension, p < 0.001, attention/memory, and p = 0.007, motor functions). MMSE scores were positively correlated with educational level (p < 0.017), but were not associated with age, recent drug use, or years of drug use. Educational level moderated the impact of substance use on MMSE performance, especially total score and composite language comprehension score. Individuals with a low educational level (≤ 8 years) had worse performance than those with a high educational level (≥ 9 years), mainly in individuals with AUD (p < 0.001).

Discussion
Individuals with a low educational level and alcohol use are more prone to present cognitive impairment than crack cocaine users, especially involving language aspects. Better-preserved cognitive function could impact treatment adherence and might guide the decision of therapeutic strategies.