Mild cognitive impairment in old-age depression is associated with increased EEG slow-wave power

Reversible dementia in geriatric depression is known to be a risk factor fo r irreversible dementia. Whether just mild cognitive deficits in elderly de pressed patients hold a similar risk is not known yet. it may be suggested that elderly depressed patients with mild cognitive deficits, who are prone to develop dementia, show EEG alterations similar to those observed in dem ented patients. We studied the relationships between cognitive performance, severity of depressive symptoms and quantitative EEG parameters in 31 unme dicated, nondemented, depressed patients aged 60 years or more. Twenty-one of the patients showed a cognitive performance characteristic of mild cogni tive impairment. In these patients, the mean delta and theta power was sign ificantly higher than in the patients without cognitive impairment. Total d elta power was negatively correlated with cognitive performance. There was no relationship between cognitive performance or EEG parameters and the sev erity of depression.