It is always interesting to contrast our observation-based hypothesis with the results obtained by other authors. We previously concluded that patients with amnestic mild cognitive impairment who have depression at baseline are at an increased risk for Alzheimer disease.1 In a series of 46 patients with amnestic mild cognitive impairment, depression was not associated with an increased risk for Alzheimer disease: only 8 of 22 depressed patients developed dementia in comparison with 17 of 24 nondepressed patients. This conclusion is at odds with previous reports indicating that depression in the elderly is a risk factor for dementia. The authors observed improvement in depressive symptoms after treatment with antidepressants on the basis of changes in the short form of the Geriatric Depression Scale. I intend to argue further in favor of our hypothesis.
Modrego PJ. Depression Is Unrelated to Conversion to Dementia in Patients With Mild Cognitive Impairment—Reply. Arch Neurol. 2005;62(3):505-506. doi:10.1001/archneur.62.3.505-b