The effects of major depression on the verbal learning and memory performance of elderly outpatients on the California Verbal Learning Test

The California Verbal Learning Test (CVLT) is a widely used measure of verbal learning and memory; however, there is little empirical evidence about the effects of major depression on the learning and memory performance of older depressed outpatients on the CVLT. The present study compared the learning and memory performance of 53 outpatients with unipolar major depression and 60 nondepressed control participants on 11 variables of the CVLT: (1) List A, Trials 1--5, (2) Short-Delay Free Recall, (3) Short-Delay Cued Recall, (4) Long-Delay Free Recall, (5) Long-Delay Cued Recall, (6) List B versus List A Trial 1 Recall, (7) Short-Delay Free Recall versus List A Trial 5 Recall, (8) Semantic Cluster Ratio, (9) Serial Cluster Ratio, and (10) Learning Slope, and (11) Recognition. The results of this study indicated that late-life depression did have a significant effect on overall verbal learning for elderly outpatients. In addition, this study provided evidence suggesting impairments in encoding for the depressed group, as evidenced by significantly lower scores on long-delay recall and recognition. This study did not reveal any significant proactive or retroactive interference, indicating that there are minimal effects of depression on storage of information. The data also indicated that older depressed individuals used semantic clustering, a type of active learning strategy, less frequently than control participants. The study contributed to the existing body of literature on late-life depression and memory by concluding that moderately depressed elderly outpatients display an identifiable pattern of explicit verbal learning and memory deficits. The strengths and limitations of this study were addressed. The clinical implications of these findings, as well as directions for future research in this area are also discussed.