P3‐139: Crossword puzzles delay onset of accelerated cognitive decline in preclinical dementia, contributing to cognitive reserve

Persons destined to develop dementia experience an accelerated rate of decline in cognitive ability, particularly in memory. The cognitive reserve hypothesis predicts that persons with greater reserve have delayed onset of this accelerated decline, followed by more rapid decline proximal to diagnosis. We have previously shown this effect for early life education, and for participation in cognitively stimulating leisure activities later in life, suggesting each as either a cause or as a marker for reserve. In this work we consider the cognitive reserve properties of specific individual cognitively stimulating activities. We followed 488 initially cognitively intact community-residing individuals with epidemiologic, clinical, and cognitive assessments every 12 to 18 months in the Bronx Aging Study. We assessed the influence of self-reported participation in six cognitively stimulating leisure activities reading, writing, crossword puzzles, board or card games, group discussions, and playing music on the onset of accelerated memory decline as measured by the Buschke Selective Reminding Test in 101 individuals who developed incident dementia. The onset of accelerated decline was estimated by modeling longitudinal cognitive data using change point models. The 17 participants who reported working crossword puzzles had their accelerated decline begin 2.85 years prior to diagnosis, while the 84 participants who did not report working crossword puzzles had their accelerated decline begin 5.43 years prior to diagnosis, a significant difference (p=.006). Decline was more rapid in the participants reporting crossword puzzle participation (5.22 vs. 2.02 points per year, p=.011). Addition of self-reported years of formal education to the model as a possible confounder or mediator did not change these relationships. None of the other leisure activities were associated with changes in the natural history of memory decline. Self-reported history of working crossword puzzles shows the strongest cognitive reserve effect seen to date. Further research is needed to ascertain the particular characteristics of crossword puzzles that are responsible for this effect, and to identify the biological substrate of reserve. The strength of the effect may motivate future cognitive interventions that could have a significant public health impact.