Why some minds bend, not break: an exploratory study of cognitive and psychological performance across levels of cognitive reserve in subjective cognitive decline.

Introduction: Subjective Cognitive Decline (SCD) is a heterogeneous at-risk condition along the Alzheimer's disease continuum, characterized by cognitive complaints despite preserved neuropsychological performance. Cognitive reserve (CR) may help explain individual differences in resilience to early cognitive and psychological vulnerability. This exploratory cross-sectional study examined whether global and domain-specific CR-education, occupational activity, and leisure time - were associated with differences in cognitive and psychological functioning in individuals with SCD. Methods: Fifty-one older adults with SCD underwent a comprehensive neuropsychological assessment and self-report measures of subjective complaints, depressive symptoms, and anxiety. Non-parametric analyses compared performance across low, medium, and high CR levels. Results: Cognitive performance was globally preserved, while depressive symptoms were clinically relevant in a substantial proportion of participants. Selective CR-related differences emerged: higher global CR was associated with better visuospatial-constructive performance; lower leisure-time CR was associated with faster performance on attentional and executive tasks; and occupational CR showed a non-monotonic association with depressive symptoms, with lower scores in the medium CR group. No differences emerged in other cognitive domains. Discussion: These findings support a multidimensional and domain-specific conceptualization of CR in SCD and highlight the clinical value of integrating CR into early cognitive aging assessment.