Self‐reflection is associated with markers of Alzheimer’s disease in cognitively unimpaired older adults

Abstract

AbstractBackgroundSelf‐reflection is conceptualised as an introspective process that involves active evaluation of one’s thoughts, feelings and behaviours. Engagement in self‐reflection is thought to yield more adaptive stress responses, that in turn result in better short‐term (e.g., reduced inflammatory responses to stressors) and long‐term (e.g., recovery from major depression) outcomes. Despite self‐reflection’s known protective effect against adverse health outcomes, the association between self‐reflection and Alzheimer’s disease (AD) risk is unknown.MethodBaseline data from 134 healthy older adults (mean age=69.3) enrolled in the Age‐Well clinical trial and 125 older adults with subjective cognitive decline (mean age=72.5) from the SCD‐Well clinical trial were included. All participants completed an assessment of self‐reflection. Modified versions of the Preclinical Alzheimer’s Cognitive Composite 5 were used to measure global cognition in both cohorts. Additionally, in Age‐Well, glucose metabolism and amyloid deposition were assessed with PET scans, and the Lifestyle‐for‐Brain‐Health (LIBRA) AD‐risk index computed to assess health and lifestyle behaviours. Separate linear regressions were run to determine associations between self‐reflection levels and AD markers (i.e., global cognition, glucose metabolism, and amyloid deposition). Analyses adjusted for available prognostic characteristics associated with AD (e.g., age, sex, education and APOE4 status) and levels of psychological distress (i.e., depression and rumination). Furthermore, to explore the potential mechanism linking self‐reflection with AD markers, the relationship between self‐reflection and LIBRA scores was investigated.ResultSelf‐reflection was positively associated with global cognition in both cohorts (Age‐Well: β=0.18, p=0.023; SCD‐Well: β=0.20, p=0.024) and glucose metabolism (Age‐Well: β=0.29, p=0.027; see Figure). No relationship, however, was found with amyloid deposition (Age‐Well: β=0.13, p=0.198). Self‐reflection was associated with LIBRA scores (Age‐Well: β=‐0.31, p=0.002), with lower self‐reflection levels associated with poorer health and lifestyle behaviours.ConclusionSelf‐reflection was associated with higher glucose metabolism, and with better global cognition in two independent older adult cohorts. For the first time, we introduce preliminary support for self‐reflection as a potential protective factor against AD‐related decline. Furthermore, the results suggest that self‐reflection may affect AD risk by influencing health and lifestyle behaviours. Both Age‐Well and SCD‐Well are clinical trials. Future work will investigate whether modifying self‐reflection via interventions affects AD markers.