Location of cerebrovascular and degenerative changes, depressive symptoms and cognitive functioning in later life: the SMART-Medea study

OBJECTIVES: Depression and cognitive impairment are highly prevalent in later life and frequently co-occur. Structural changes in critical brain regions may underlie both conditions. The authors examined associations of infarcts, white-matter lesions (WML) and atrophy at different locations with depressive symptoms and cognitive functioning.

METHODS: Within the Second Manifestations of Arterial Disease-Memory, Depression and Aging (SMART-Medea) study, cross-sectional analyses were performed in 585 non-demented patients aged ≥50 years with symptomatic atherosclerotic disease. Volumetric measures of WML and atrophy were obtained with 1.5 T MRI; infarcts were rated visually. Depressive symptoms were assessed with the Patient Health Questionnaire-9 (score ≥6). z Scores of executive functioning, memory and processing speed were calculated. Analyses were adjusted for age, sex, education, intelligence, vascular disease, physical functioning and co-occurring brain changes.

RESULTS: Depressive symptoms were present in 102 (17%) patients and were associated with poorer memory (B=-0.26, 95% CI -0.47 to -0.06). Large subcortical infarcts and lacunar infarcts in deep white-matter tracts were both associated with depressive symptoms (RR=2.66, 95% CI 1.28 to 5.54; RR=2.02, 95% CI 1.14 to 3.59) and poorer executive functioning and memory. Periventricular WML volume was associated with poorer executive functioning; cortical infarcts in the left hemisphere and media flow region, ventricular volume and cortical atrophy were associated with a slower processing speed.

CONCLUSION: In this sample of non-demented older persons, subcortical infarcts contributed to an increased risk of depressive symptoms as well as cognitive impairment. This depended on location in projecting white-matter tracts, and not on infarct size.