Depressive symptoms and executive functioning in stroke patients: a follow-up study

Background: Cognitive and emotional sequellae are commonly observed in stroke patients and these symptoms often co-occur. Diagnosis can be difficult since symptoms of depression and executive dysfunction overlap. Objective: To study the longitudinal relationship between depressive symptoms and executive dysfunction in stroke patients. Methods: The study comprises of 116 first-ever stroke patients who were followed-up for 2 years and who were assessed for emotional and cognitive sequellae after 1, 6, 12, and 24 months. Emotional disturbances were evaluated using the SCL-90 depression subscale. Executive functions were assessed using compound scores of a combination of the interference scores of the Stroop Colour Word Test and the Concept Shifting Test. Results: Twenty-five patients suffered from both depressive symptoms and executive dysfunction, 28 patients were depressed with no signs of executive dysfunction, and 13 patients showed executive dysfunction with no depressive symptoms. Patients with executive dysfunction had higher mean SCL-90D scores compared to patients with no executive dysfunction (30.9 (SD 11.7) versus 26.2 (SD 11.1, p=0.037). Depressive symptoms were predictive for executive dysfunction in a regression analysis corrected for age, sex, and diabetes mellitus but not after additional correction for pre-existent brain damage and other vascular risk factors. After 2 years 66.6 and 53.3% of patients with both depressive symptoms and executive dysfunction at baseline still had depressive symptoms and executive dysfunctions respectively and had worse prognostic outcome than patients with depressive symptoms or executive dysfunction alone. Conclusions: Symptoms of depression and executive dysfunction are highly prevalent in stroke patients and often co-occur. These patients are more at risk for poor stroke outcome, chronic depression, and cognitive deterioration.