Testing whether cognitive reserve as measured by self-rating of stimulating activities moderates the association of polysubstance use and neurocognitive disorder

Introduction: The objectives were to identify a latent factor of cognitive reserve (CR) assessed by self-rating of cognitively stimulating activities, to analyze the association between this factor and educational attainment, and to test whether CR moderates the association between polysubstance use and neurocognitive disorder (NCD). Methods: Cross-sectional data of 753 participants was collected in Mexico City. A questionnaire for self-rating of stimulating activities (work/education, leisure, physical, social, usual- and current environments) was designed. Confirmatory factor analysis was performed to test unifactoriality. This CR factor was then used within a structural equation model of moderation between recent- and years of substance use and indicators of NCD (Montreal Cognitive Assessment and an interview for subjective cognitive deficits). Results: We found acceptable goodness-of-fit values for the unifactorial model, but no association of this factor with educational attainment, nor with recent- and years of substance use (suggesting independence of CR and severity of neuropathology). We did not find a moderation effect of CR between substance use and indicators of NCD; CR was negatively associated with subjective cognitive deficits only. Conclusions: Moderation effect of self-rated CR should be further tested using direct measures of substance-induced neuropathology. Measurement of self-rated CR may complement self-reported cognitive examination.