Post-stroke depression, but not anxiety, is independently associated with executive and visuospatial function: a five-year longitudinal cohort study

Background. Post-stroke anxiety and depression frequently co-occur, and whether each is independently associated with cognitive impairment remains unclear because most studies model one without adjusting for the other variable. In a five-year cohort, we tested whether anxiety and depression have distinct cognitive correlates and whether early affective status predicted subsequent cognitive recovery. Methods. Patients from the STROKDEM cohort were assessed at 6, 12, 36, and 60 months post-stroke for anxiety, depression, and five cognitive domains (memory, executive functioning, attention, visuospatial functioning, and language). Two symmetric random-intercept linear mixed models regressed each affective score on the cognitive domains while adjusting for other scores. Repeated-measures correlations, multiple imputations for attrition, and exploratory trajectory and prognostic models were also used. Results. After mutual adjustment and correction, depression was independently associated with executive and visuospatial function, whereas anxiety showed no independent cognitive correlation. Repeated-measures correlation confirmed this dissociation. The anxiety findings were stable across the sensitivity analyses and multiple imputations. Attrition was selective for baseline cognition, and exploratory associations between early affect and cognitive recovery did not survive multiple imputations and were inconclusive. Limitations. Attrition was substantial and selective on baseline cognition; the persistent anxiety subgroup was small, limiting the power for trajectory analyses; and psychiatric history, psychotropic medication, and cognitive reserve beyond education were unavailable. Conclusions. The cognitive burden of post-stroke affective disorders is carried by depression, rather than anxiety. Because anxiety-related cognitive impairment largely reflects comorbid depression, screening for depression rather than anxiety alone may better identify stroke survivors at risk of cognitive impairment.