Despite the body of literature on genetic risk factors for dementia, little is known on protective genetic factors associated with favourable cognitive ageing in the oldest population.

The gap

Consensus across the literature

Supporting evidence — 6 representative gaps

• Social determinants of health, behavioral factors, and incident dementia: a prospective cohort study (2026) · doi

  This study has several strengths. It was conducted using a large-scale, population-based, and prospective cohort design with long follow-up periods. The enhanced sta- tistical power and rich data may help in obtaining more robust and reliable findings. We also considered effects of genetic predisposition (APOE ε4 status) on the associa- tion of unfavorable factors with incident dementia risk, and released consistent findings. However, limitations in this study should also be noted. First, due to the inher- ent drawbacks of observational studies, the associations of SDoH and behavioral factors with incident dementia were merely correlational rather than causal. Second, we only assessed the widely available SDoH and behavioral factors, and did not evaluate comprehensively unfavor- able factors, such as diet, chronic stress, and neighbor- hood environment. Further studies included more factors should be concluded to examine the association between unfavorable factors and dementia risk. Third, the assess- ment of dementia was based solely on the Langa-Weir algorithm derived from HRS data, rather than on for- mal clinical diagnoses. Although this algorithm is well- validated and represents the mainstream approach for large population studies like the HRS, ensuring compa- rability with prior literature [47–49], the use of a single operational definition may introduce misclassification bias. Forth, our study assessed SDoH only at the indi- vidual/household level (e.g., income); area-based indices (e.g., neighborhood deprivation) were not considered. This omission may underestimate the total burden of SDoH on dementia risk. Finally, although we controlled for many potential confounders, we cannot rule out all potential residual confounders.

  Keywords: factors dementia sdoh based risk large population considered unfavorable incident behavioral rather assessed algorithm potential
• Prevalence and correlates of behavioral and psychiatric symptoms in community‐dwelling elders with dementia or mild cognitive impairment: the Memory and Medical Care Study (2003) · doi

  BACKGROUND: Little is known about the prevalence and correlates of behavioral and psychiatric symptoms of dementia in community-dwelling elders with dementia or mild cognitive impairment (MCI).

  Keywords: dementia background little known prevalence correlates behavioral psychiatric symptoms community dwelling elders mild cognitive impairment
• Dementia in People with Severe/Profound Intellectual (And Multiple) Disabilities, and Its Natural History (2023) · doi

  Introduction: Although the prevalence of dementia increases among people with severe/profound intellectual (and multiple) disabilities (SPI(M)D), dementia in people with SPI(M)D is not yet fully understood.

  Keywords: dementia people introduction prevalence increases among severe profound intellectual multiple disabilities fully understood
• Centenarians and Oldest Olds in Liguria - COOL: a multidisciplinary study to investigate the genetic determinants of cognitive well-being in Genoa, Italy. Rationale, study protocol and cohort profile. (2026) · doi

  Despite the body of literature on genetic risk factors for dementia, little is known on protective genetic factors associated with favourable cognitive ageing in the oldest population.

  Keywords: genetic factors despite body literature risk dementia little known protective associated favourable cognitive ageing oldest
• Cognitive impairment, all-cause and cause-specific mortality among non-demented older adults (2014) · doi

  BACKGROUND: cognitive impairment is widespread among older adults even in the absence of dementia, but very little is known about the association between cognitive impairment not due or not yet converted to dementia and mortality.

  Keywords: cognitive impairment dementia background widespread among older adults even absence little known association converted mortality
• Psychiatric disorders and risk of subsequent dementia: Systematic review and meta‐analysis of longitudinal studies (2022) · doi

  Abstract Objectives Although psychiatric disorders have been found to be associated with increased risk of dementia, previous findings are mixed, and the nature of these relationships remains poorly understood.

  Keywords: abstract objectives psychiatric disorders found associated increased risk dementia previous mixed nature relationships remains poorly