STRUCTURAL AND FUNCTIONAL ABNORMALITIES IN ELDERLY PATIENTS CLINICALLY RECOVERED FROM EARLY-ONSET AND LATE-ONSET DEPRESSION

Background: Structural and functional brain changes have been describe d in elderly patients with unipolar affective disorder. Changes appear to be more marked in patients with late-onset depression, but the rev ersibility of such changes after clinical recovery is not known. Metho ds: Magnetic resonance imaging, electroencephalography (EEG), and cogn itive tests were performed in 23 elderly patients (mean age 66.5 years ) clinically recovered from major depression. Twelve had late-onset de pression (first episode over 55 years of age); 11 had early onset (fir st episode before 50 years), EEG and cognitive testing were also perfo rmed on 15 control subjects. Results: Patients with late-onset depress ion had larger third and lateral ventricles, increased ventricular-bra in ratio, and greater frequency and severity of subcortical white matt er lesions than those with early onset. There was no difference betwee n early- and late-onset patients in EEG and cognitive measures, but co mpared with controls patients showed significant changes in EEG evoked potentials and increased slow-wave activity slowed reaction times, an d global impairments in cognitive function. Conclusions: These results suggest that structural changes are greater in patients with late-ons et depression, and that EEG and cognitive impairments persist after re covery regardless of age of onset of depression, and are independent o f structural changes. Biol Psychiatry 1998;44:34-46 (C) 1998 Society o f Biological Psychiatry.