Adverse life event and risk of cognitive impairment: a 5-year prospective longitudinal study in Chongqing, China

Association of Stress with Risk of Dementia and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

Although many studies have investigated the association between stress and risk of dementia, findings are inconsistent due to the variation in the measures used to assess stress.

OBJECTIVE

We conducted a systematic review and meta-analysis to investigate the association between psychological stress (including neuroticism, stressful life events, and perceived stress) and the risk of incident dementia and mild cognitive impairment in adults.

METHODS

PsycINFO, Embase, and MEDLINE were searched to October 2020 for eligible observational, prospective studies. Of the 1,607 studies screened, 26 (24 unique cohorts) were included in the qualitative analysis and 16 (15 unique cohorts) were included in the quantitative analysis.

RESULTS

Across studies, higher perceived stress was significantly associated with an increased risk of mild cognitive impairment (Cases/Total N = 207/860: hazard ratio [HR] = 1.19, 95% confidence interval [CI] = 1.03-1.38) and all-cause dementia (Cases/Total N = 203/1,882: HR = 1.44, 95% CI = 1.07-1.95). Exposure to two or more stressful life events (versus none) was significantly associated with an increased risk of all-cause dementia (Cases/Total N = 3,354/11,597: HR = 1.72, 95% CI = 1.14-2.60), while one or more stressful life events was not. Higher neuroticism was significantly associated with an increased risk of Alzheimer's disease dementia (Cases/Total N = 497/4,771: HR = 1.07, 95% CI = 1.01-1.12), but not all-cause dementia.

CONCLUSION

This review suggests that psychological stress in adulthood is associated with an increased risk of dementia. Further research is needed to clarify the mechanisms underlying these associations.

EPA guidance on mental health and economic crises in Europe

This European Psychiatric Association (EPA) guidance paper is a result of the Working Group on Mental Health Consequences of Economic Crises of the EPA Council of National Psychiatric Associations. Its purpose is to identify the impact on mental health in Europe of the economic downturn and the measures that may be taken to respond to it. We performed a review of the existing literature that yields 350 articles on which our conclusions and recommendations are based. Evidence-based tables and recommendations were developed through an expert consensus process. Literature dealing with the consequences of economic turmoil on the health and health behaviours of the population is heterogeneous, and the results are not completely unequivocal. However, there is a broad consensus about the deleterious consequences of economic crises on mental health, particularly on psychological well-being, depression, anxiety disorders, insomnia, alcohol abuse, and suicidal behaviour. Unemployment, indebtedness, precarious working conditions, inequalities, lack of social connectedness, and housing instability emerge as main risk factors. Men at working age could be particularly at risk, together with previous low SES or stigmatized populations. Generalized austerity measures and poor developed welfare systems trend to increase the harmful effects of economic crises on mental health. Although many articles suggest limitations of existing research and provide suggestions for future research, there is relatively little discussion of policy approaches to address the negative impact of economic crises on mental health. The few studies that addressed policy questions suggested that the development of social protection programs such as active labour programs, social support systems, protection for housing instability, and better access to mental health care, particularly at primary care level, is strongly needed.

Stress, PTSD, and dementia

The physiological consequences of acute and chronic stress on a range of organ systems have been well documented after the pioneering work of Hans Selye more than 70 years ago. More recently, an association between exposure to stressful life events and the development of later-life cognitive dysfunction has been proposed. Several plausible neurohormonal pathways and genetic mechanisms exist to support such an association. However, many logistical and methodological barriers must be overcome before a defined causal linkage can be firmly established. Here the authors review recent studies of the long-term cognitive consequences of exposures to cumulative ordinary life stressors as well as extraordinary traumatic events leading to posttraumatic stress disorder. Suggestive effects have been demonstrated for the role of life stress in general, and posttraumatic stress disorder in particular, on a range of negative cognitive outcomes, including worse than normal changes with aging, Alzheimer's disease, and vascular dementia. However, given the magnitude of the issue, well-controlled studies are relatively few in number, and the effects they have revealed are modest in size. Moreover, the effects have typically only been demonstrated on a selective subset of measures and outcomes. Potentially confounding factors abound and complicate causal relationships despite efforts to contain them. More well-controlled, carefully executed longitudinal studies are needed to confirm the apparent association between stress and dementia, clarify causal relationships, develop reliable antemortem markers, and delineate distinct patterns of risk in subsets of individuals.