Frontal and parietal lobe dysfunction in depression: delayed alternation and tactile learning deficits.

To evaluate frontal and parietal lobe involvement in depression, behavioral tests sensitive to damage in these regions were administered to depressed patients over age 50. Delayed alternation (DA), delayed response and object alternation were used to assess dorsolateral frontal and orbitofrontal function. Tactile learning problems (TOL and TRL) assessed parietal lobe integrity. Depressed patients were significantly impaired on DA, TOL and TRL, suggesting spatial memory (DA) and tactile learning deficits. The functional neuroanatomy underlying these deficits may share features with Parkinson's and Alzheimer's diseases.