Increase in number of depression symptoms over time is related to worse cognitive outcomes in older adults with type 2 diabetes

This study was intended to assess whether and how simultaneous changes in depression are associated with cognition over time in >1,000 initially cognitively normal older adults (≥ 65 years old) with T2D. Researchers included a total of 1,021 individuals (mean age 71.6 [SD=4.6]; 41.2% female), who were initially cognitively normal participants of the Israel Diabetes and Cognitive Decline study and who had been assessed for depression and cognition about every 18 months. The results of this study indicate that an increase of depressive symptoms over time is correlated with parallel cognitive decline, demonstrating that the natural course of the two conditions progresses concurrently and implying common underlying mechanisms" in elderly with T2D. Lower baseline cognitive scores in global cognition, executive functions, semantic categorization and episodic memory, but not rate of decline in any cognitive domain, were significantly linked with a higher number of depression symptoms at baseline. Worse cognitive outcomes in global cognition, semantic categorization and in episodic memory was associated with a larger increase in number of depression symptoms during follow-up, but the size of this effect was constant over time.