Depressive symptoms are frequent in Alzheimer's disease (AD), but it is controversial whether depression is a risk factor for AD. This study measured for the first time cortical amyloid-β (Aβ) levels using [(11)C] Pittsburgh Compound B (PiB) positron emission tomography (PET) in a group of nondemented patients with prior depressive episodes. Twenty-eight elderly patients (mean age 61 years, range 51-75, 18 women) with onset of first depressive episode more than 6 years ago but now remitted from depression and 18 healthy subjects (mean age 61 years, range 50-76, 12 women) were included.