Objective: Elderly patients with cardiovascular disease (CVD) often report cognitive difficulties including reduced cognitive processing speed and attention. On cross-sectional examination, such reports relate more closely to mood than to objective measures of cognitive performance, thus questioning the validity of subjective cognitive complaints as a marker of neurodegenerative processes. This study examined the longitudinal relationship among self-reported cognitive difficulties, depression, and performance on objective tests of global cognition in patients with CVD.
Participants and methods: Forty-seven patients with CVD (aged 55-85 years) completed a measure of perceived cognitive dysfunction (Cognitive Difficulties Scale [CDS]), a medical history questionnaire, the Dementia Rating Scale (DRS), and the Beck Depression Inventory (BDI) at baseline and 12 months later. Baseline brain imaging was available on a small subsample (N = 17).
Results: Hierarchical linear regression revealed that increased report of cognitive difficulties at baseline was significantly associated with poorer DRS performance at follow-up (F[3, 43] = 4.45, p = 0.008, CDS partial r = -0.30, p = 0.048), independent of age, education, baseline DRS, and BDI scores. Greater perceived cognitive dysfunction at baseline also related to higher level of white matter lesions (r = 0.53, df = 15, p = 0.028).
Conclusions: Self-reported cognitive difficulties may reflect early changes in cognitive aging that are difficult to detect using global cognitive screening measures at a single time point. However, these perceived difficulties relate to objectively measured cognitive decline over time. Thus, they may provide important clinical information about early neurodegenerative processes that should be carefully monitored.