Biomarkers and Depressive Symptoms in Older Women with and without Cognitive Impairment

A number of biological markers have been implicated in late life depression with inconsistent results. The present study examined the relationship between several serum based biomarkers and symptoms of depression in a sample of elderly women with AD or cognitively intact. Methods 171 females (58 with AD and 113 cognitively intact) were recruited from the Longitudinal Research Cohort of the Texas Alzheimer’s Research and Consortium (TARC). Stepwise regressions were conducted with GDS total and subscales and a panel of biomarkers (CRP, IL-10, IL-1α, TNF-α, ICAM-1, BDNF, and MIF). ApoE4 status was coded (carrier or non-carrier), and the results were analyzed by cognitive status (AD or controls). Results: None of the biomarkers significantly predicted total GDS score for AD cases, controls or sample as a whole. For the Controls, ICAM significantly predicted Dysphoria and level of Apathy. Among AD patients, MIF, ICAM, and CRP, were significantly associated with Apathy. MIF and ICAM were inversely associated with reported Apathy. CRP was positively associated with Apathy. CRP was also positively related to level of perceived Cognitive Impairment. Conclusions: The present study was one of the first to examine biomarkers related to depression symptoms in elderly women with AD and normal controls. For Controls ICAM alone predicted level of apathy. In the AD group, MIF, CRP, and ICAM were significantly associated with apathy. More research examining the relationship between biomarkers and depression is needed in older patients with and without cognitive impairment across genders.