Cognitive performance in older and middle-aged depressed outpatients and controls

Cognitive performance was assessed in older (60-75 years) and middle-aged (40-59 years) unmedicated outpatients with major depression and in healthy controls to examine potential interactive effects of age and depression. Cognitive performance was assessed from three categories of tasks: verbal, visual-spatial, and visuo-motor scanning tasks. Depressed subjects did not perform as well as controls on visuo-motor scanning tasks that included the Trail Making Tests A and B, and the Symbol Digit Modalities Test. Likewise, the older compared to the middle-aged group was slower on the visuo-motor scanning tasks. In addition, the older group showed poorer performance on visual-spatial tasks. Neither depression nor age group effects were observed for the primarily verbal tasks. Age and depression combined in an additive (noninteractive) fashion such that the older depressed subjects performed worse than the middle-aged depressed subjects, and older and middle-aged controls, on visuo-motor scanning tasks.