Increased C‐reactive protein is not associated with apathy: the Leiden 85‐Plus Study

BACKGROUND: Apathy has recently been recognized as a distinct clinical syndrome although it is difficult to differentiate from late life depression. In old age, apathy as a syndrome in itself and depression may have different etiologies. Inflammatory markers have been associated with depression in the elderly, but the relation with apathy is unknown. OBJECTIVE: To assess the relation between C-reactive protein (CRP) and apathy as a syndrome in itself, apart from depression, in subjects aged 85 and older. METHODS: All data come from the Leiden 85-Plus Study, a prospective, population-based study of 599 elderly subjects. CRP was measured at baseline. In all subjects with a Mini Mental State Examination (MMSE) > or = 19 points (n = 500), apathy and depression were assessed annually from age 85 to 90 using the three apathy and twelve depression questions of the 15-item Geriatric Depression Scale (GDS-15). The association between CRP and apathy or depressive symptoms was assessed both at baseline and longitudinally. RESULTS: At baseline, no association was found between CRP-concentration and apathy or depression. In subjects free of apathy and depression at baseline, subjects in the highest CRP-tertile at baseline had significantly more increase in depressive symptoms but not in apathy symptoms during follow-up. CONCLUSION: Higher CRP concentrations increased the risk of depression but not apathy in a community-based cohort of 85 years old subjects. This suggests that apathy and depression in old age have different etiologies.