Lifespan- and depression-related changes to associative memory

Associative memory may be more sensitive to both lifespan development and to affective disorders than item memory. However, lifespan and depression-related effects on associative versus item memory have never been investigated in a single study, and to date it is unclear whether associative memory difficulties are similar in children, older adults and depressed individuals. Here, two groups of patients in therapeutic treatment for a depressive disorder (kids/adolescents and middle-aged adults), as well as non-depressed individuals of four age groups (kids/adolescents, young adults, middle-aged and older adults) completed a word pair encoding task followed by associative recognition. Both item and associative memory followed an inverted U-shaped pattern across the lifespan, which was more pronounced for associative memory, with lower performance in non-depressed kids/adolescents and in older adults, compared to young adults and the middle-aged scoring in between. In addition to a general reduction in memory performance, both depressed groups also showed reduced associative, relative to item, memory. Kids/adolescents, older adults and depressed patients were less likely to retrospectively report having used an effective encoding strategy, and statistically accounting for strategy use abolished the disproportionate reductions of associative versus item memory. Taken together, this study revealed evidence for an "associative memory deficit" in children and older adults, which is enhanced in patients with depressive disorders, and for a key role of strategic factors therein.