Accelerated forgetting in memory clinic patients with subjective cognitive decline: Results from a 7-day follow-up long-term retrieval assessment

BackgroundSubjective cognitive decline (SCD) is recognized as an early indicator of preclinical Alzheimer's disease (AD). However, individuals with SCD do not exhibit cognitive impairment on standard neuropsychological tests. Accelerated forgetting (AF) has been reported in individuals with preclinical AD and is characterized by intact learning and early retention but impaired retrieval after several days. Currently, AF is not captured by standard neuropsychological testing.ObjectiveThe present study investigated recall performance in memory clinic patients with SCD, without impairment on standard cognitive tests, during a 7-day follow-up telephone assessment for detecting AF.MethodsOne week after completing the neuropsychological assessment, participants underwent a structured telephone-based follow-up interview. This included various measures of verbal and visual memory. AF was operationalized as the rate of forgetting between initial recall and 7-day delayed recall.ResultsData from 35 individuals with SCD, who showed no cognitive impairment on standard tests, and 54 healthy controls (HC) were analyzed. Although there were no significant differences between the groups in learning and short-delay memory performance, after seven days, the SCD group showed lower recall and a higher forgetting rate on the FCSRT-IR free and total recall measures compared to the HC group.ConclusionsAF can be detected using a brief, telephone-based assessment in cognitively unimpaired participants with SCD. It could bridge the gap between subjective and objective memory decline. Further research is necessary to improve potential follow-up assessments in neuropsychological testing and to investigate the link between AF and AD biomarkers and memory decline.