This paper presents the analyses of limitations in working memory functions among older adults in comparison to depressed students and to appropriate control participants. The first part reviews the newest findings from the neuroimaging studies on working memory among depressed and older adults. These studies showed some interesting similarities in activation of brain regions involved in working memory functioning and its specific pattern in either depressed or elder persons. The next part presents the reanalysis of the performance of more or less complex working memory tasks by depressed and older adults. In these reanalyses the authors applied the Brinley plots for comparing results from different populations and from tasks of varied difficulty. After reviewing research findings they suggest that both old age and depression may limit the working memory functioning, but the mechanisms of these limitations are different in each group.