Background: Time trends for dementia prevalence and incidence rates have been reported over the past seven decades in different countries and some have reported a decline. Objective: To undertake a systematic review to critically appraise and provide an evidence-based summary of the magnitude and direction of the global changes in dementia prevalence and incidence across time. Methods: Medline, EMBASE, and PsychINFO were searched for studies focused on secular trends in dementia prevalence and/or incidence until 18 December 2017. In total, 10,992 articles were identified and 43 retained. Results: Overall, prevalence rates are largely increasing (evidence primarily from record-based surveys and cohort studies in Japan, Canada, and France) or have remained stable (evidence primarily from cohort studies in Sweden, Spain and China). A significant decline in prevalence has however been reported in more recent studies (i.e., from 2010 onwards) from Europe (e.g., UK and Sweden) and the USA. Incidence rates have generally remained stable or decreased in

Considerable international governmental support is focused on the timely diagnosis of dementia and post-diagnostic care of people with dementia. Identifying those at high risk of dementia is one approach to timely diagnosis. General practitioners (GPs) are well-placed clinicians in the community to provide both pre- and post-diagnostic dementia care. However, GPs have in the past consistently demonstrated low confidence in both diagnosing dementia and providing care for these complex patients particularly for patients in the post-diagnostic phase. It is currently unclear how future GPs view dementia care. We aimed to evaluate the current attitudes and experiences of future GPs in dementia care and their views on targeting high risk groups. All (n = 513) GP trainees were approached by email to participate in a cross-sectional web and paper-based survey in the North of England. A further reminder was sent out two months after the initial invitation. We received 153 responses (29.8% response rate, 66.7% female, average age 31 (range 25-55 years old). The main difficulties encountered included coordinating supporting services for carers and the person with dementia and responding to co-existing behavioral and psychiatric symptoms. Further education in dementia management was considered to be important by respondents. GP trainees were generally very positive about their future role in caring for people with dementia, particularly in the area of earlier diagnosis via identification of high-risk individuals. Future GPs in one area of England are very positive about their key role in dementia care. In order to facilitate the delivery of high quality, community-based care, work is required to establish core post-diagnostic dementia support services. Further research is needed to identify effective systems to enable accurate assessment and to ensure earlier diagnosis in high-risk groups.

The worldwide prevalence of dementia is predicted to rise significantly in the next three decades. However, these projections have not taken into account the role of modifiable risk factors and whether any prevention strategies might influence the predicted trend. Attempts at pharmacological disease modification have largely been disappointing, and the difficulties in conducting dementia trials are reviewed here. In contrast, recent population studies in high-income countries suggest that the epidemiology may be changing with a possible decline in incident dementia, or even a reduction in age-specific prevalence. Therefore, efforts to develop public health interventions may prove to be the more successful approach to addressing dementia at a societal level.

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