Prospective memory in subjective cognitive decline: a preliminary study on the role of early cognitive marker in dementia

Accumulating evidence shows that subjective cognitive decline (SCD) without impairment on conventional neuropsychological tests may indicate increased risk for Alzheimer disease. Previous studies of mild cognitive impairment have demonstrated the potential role of prospective memory (PM) in the early detection of cognitive decline. We thus aimed to investigate the performance of people with SCD on PM tasks relative to their healthy controls (HCs). Forty-one participants with SCD and demographically matched HCs received regular cognitive testing as well as 2 single-trial naturalistic time-based and event-based PM tasks. Statistical analyses showed that the individuals with SCD performed worse on the time-based PM task, especially on the prospective component, when compared with their HCs. Our findings suggest that PM, especially the time-based one on the prospective component, may be an early cognitive marker of dementia. This implies an underlying difficulty among subjects with SCD in self-initiation that exacerbates their memory difficulties. Further investigation on a large scale is needed.