Clinical and cognitive correlates of structural hippocampal change in "at-risk" older adults

With estimates of dementia expected to rise over the coming decades, there is interest in understanding the factors associated with promoting neuroprotection and limiting neurodegeneration. In this study, we examined the change in the volume of the hippocampus over a 2-month period in 34 older people ''at risk'' of cognitive decline (mean age = 66.8 years, 38% male). Factors that were examined included cognitive reserve, neuropsychological functioning, depression as well as a lifestyle (cognitive training) intervention. The results showed that over a 2-month period, increases in hippocampal size were associated with having higher premorbid intellect, greater occupational attainment, superior memory, and higher levels of functioning. Conversely, depression and disability were associated with decreases in hippocampal volume. Cognitive training was not associated with changes in hippocampal volume. These findings suggest that factors associated with cognitive reserve, cognition and depression may play an integral pathophysiological role in determining hippocampal volumes in ''at-risk'' older adults.