Cognitive Reserve Moderates the Relationship between Executive Functioning and Depression in Long-term Stroke

Background: This study aimed to investigate whether pre-stroke cognitive reserve moderates the relationship between executive dysfunction and depressive symptoms in long-term stroke survivors. We hypothesized that higher post-stroke executive dysfunction scores would be associated with higher depressive symptom scores, and that greater pre-stroke cognitive reserve would attenuate this association. Method: This study utilized data from the OX-CHRONIC study, involving 105 remotely-assessed long-term stroke survivors at approximately 4.57 years post-stroke. Depressive symptoms were measured using the Hospital Anxiety and Depression Scale, and executive dysfunction was assessed using the Oxford Cognitive Screen (OCS), OCS-Plus, Rey-Osterrieth Complex Figure Test, Delis-Kaplan Executive Function System, Hayling Sentence Completion Test, and Backwards Digit Span. Cognitive Reserve was measured using the Cognitive Reserve Index questionnaire (CRIq), including education, working activity, and leisure activity subscales. Multiple regression models evaluated the moderating effect of Cognitive Reserve on executive dysfunction and depressive symptoms.Results: Higher executive dysfunction scores were significantly associated with higher depressive symptom scores (ρ = -.32, p = .003). Cognitive Reserve moderated this relationship, with higher levels of pre-stroke Cognitive Reserve strengthening the relationship between executive functioning and depressive symptoms (interaction term: β = -0.04, p = .01). Exploratory analyses revealed that the education subscale of CRIq significantly moderated this relationship (β = -0.06, p = .002), while working and leisure activities did not.Conclusions: Pre-stroke Cognitive Reserve, particularly educational attainment, may strengthen executive function’s protective effect on depressive symptoms in long-term stroke. This underscores the importance of fostering cognitively stimulating activities throughout the lifespan to enhance resilience against post-stroke cognitive and emotional challenges.