Subjective Cognitive Decline (SCD) plus is a consensus-based set of features linked to higher Alzheimer’s disease (AD) risk. These features are typically studied as isolated risk factors, but in practice could be viewed as an inter-related system due to their co-occurrance. Bayesian networks can quantify evidence for and against existence of conditional dependence, providing a robust picture of relations within the SCDplus construct and with other AD (bio-)markers. 

This study aims to investigate the conditional relationships among SCD plus features, APOE4 carriership, and amyloid pathology in a cognitively unimpaired memory clinic population.

In a relatively sparse network, we found strong evidence for both presence and absence of interrelations among SCDplus features and between these features and biological AD risk markers. Amyloid positivity was more likely in case of complaint onset after age 60. APOE4 was largely isolated from SCD plus, but less likely if there was informant confirmation of decline. The varied interrelations point to heterogeneity in the SCDplus construct and in terms of the relevance of its features for biological AD markers.