Dementia and aging populations-A global priority for contextualized research and health policy

Competing interests: I have read the journal's policy and have the following conflicts: CB and BM are members of the Editorial Board of PLOS Medicine and Guest Editors for the Dementia Special Issue. There is increasing realization that public health measures will play an important role in the drive to protect world populations from cognitive impairment and dementia, but there is relatively little research in this area, acknowledgement of lack of knowledge (e.g., recent road map) and a wide variability in actions taken to address these in different societies and certainly in their effectiveness. In parallel, research studies published in this special issue also help to advance understanding of genetics and dementia, emphasizing a heterogeneity of risk factors for different individuals and populations. By contrast, Lipnicki and colleagues report on harmonized longitudinal data for 14 cohorts from 12 countries [10]: different rates of cognitive decline were seen for those of different ethnicity, for men versus women, and for apolipoprotein [epsilon]4 carriers. [...]Campion and colleagues describe a French cohort in which polymorphisms and known mutations in APP, PSEN1, and PSEN2 were found in a population with early-onset AD, including sporadic cases [12]. Fine-mapping of the human leukocyte antigen (HLA) locus as a risk factor for Alzheimer's disease: A Case-Control Study, Lipnicki DM et al. Age-related cognitive decline and associations with sex, education and apolipoprotein E genotype across ethno-cultural groups and geographic regions: a collaborative cohort study Blacker D et al.