DIFFERENTIATION OF DEMENTIA AND DEPRESSION BY MEMORY TESTS - A METAANALYSIS

The many tasks used for clinical memory assessment have not been compa red systematically for their usefulness in differentiating dementia an d depression in old age. The aim of this meta-analysis was to identify those attributes of memory tasks that show high discriminative power. Eighty-nine effect-sizes were calculated out of 16 publications direc tly comparing demented and depressed patients. Outliers in the effect- size distribution (5% of the highest values) were excluded. The groups could be significantly better differentiated by delayed retrieval tas ks rather than immediate retrieval tasks. Tasks with distraction befor e retrieval reached higher effect sizes than retrieval tasks without d istraction. Tasks of high-capacity demand differentiated the groups si gnificantly better than tasks of moderate and low demand. Effect-size magnitude was not influenced by patient characteristics except severit y of dementia. Thus, demented and depressed patients may best be diffe rentiated by a memory task that uses delayed retrieval with distractio n.