Murray A, McNeil C, Salarirad S, et al.
Arch Gerontol Geriatr 2016;63:49-54
Publication date: March 1, 2016
Brain hyperintensities, detectable with MRI, increase with age. They are associated with a triad of impairment in cognitive ability, depression and physical health. Murray et al. tested the hypothesis that the association between hyperintensities and cognitive ability, physical health and depressive symptoms depends on lesion location.
244 members of the Aberdeen 1936 Birth Cohort were recruited in this study. 227 participants completed brain MRI and their hyperintensities were scored using Scheltens’ scale. 205 had complete imaging, cognitive, physical health and depressive symptom score data. The relationships between hyperintensity location and depressive symptoms, cognitive ability and physical health were examined by correlation and structural equation analysis.
Authors found that depressive symptoms correlated with hyperintensity burden in the grey matter (r=0.14, P=0.04) and infratentorial regions (r=0.17, P=0.01). Infratentorial hyperintensities correlated with reduced peak expiratory flow rate (r=-0.26, P<0.001) and impaired gait (r=0.13, P=0.05). No relationship was found between white matter and periventricular (supratentoral) hyperintensities and depressive symptoms. Hyperintensities in the supratentorial and infratentorial regions were associated with reduced cognitive performance. Using structural equation modelling authors found that the association between hyperintensities and depressive symptoms was mediated by negative effects on physical health and cognitive ability.
Hyperintensities in deep brain structures are associated with depressive symptoms, mediated via impaired physical health and cognitive ability. Participants with higher cognitive ability and better physical health are at lower risk of depressive symptoms.