Association between stress-related disorders and the risk of dementia using the Korean National Sample Cohort: a matched cohort study

[Association of lifetime traumatic events and mild Neurocognitive Disorder in old age]

The evidence on the association between lifetime traumatic events (LTE) and the occurrence of cognitive changes and dementia is heterogeneous and often based on studies in high-risk populations. Using data from a German population-based study, this study examines whether there is a connection between LTE and experiences of abuse (CA) and neglect (CN) in childhood with mild Neurocognitive Disorder (miNCD) in old age.889 participants were included in the analysis. The trauma list of the PTSD module of the Structured Clinical Interview for DSM-IV (SKID-I) and the Childhood Trauma Screener (CTS) were used to record LTE. miNCD was diagnosed using a neurocognitive test battery according to DSM-5 criteria. Binary logistic regression analyses were used to examine the extent to which the presence LTE is related to the presence of miNCD.In the sample 31.0% reported at least one LTE, 30.3% reported CN and 13.2% reported CA. 19.1% met the criteria for miNCD. Four models were tested, including age, gender and educational level as possible confounding variables. Model 1 examined whether LTE (yes/no) was associated with miNCD in old age. Model 2 tested whether the number of LTE was related to miNCD. Model 3 tested whether CN was related to miNCD, and model 4 tested whether CA was related to miNCD. None of the models showed a significant effect of the investigated variables on the occurrence of miNCD.International studies show indications of a correlation between TLE, CN, CA and miNCD, but there is a lack of corresponding studies in Germany. Despite methodological strengths (standardized recording of all variables, population-based study), our analysis found no correlations. Maybe study requirements led to a positive selection of healthy older people. Nevertheless, LTE, CA and CN were not underrepresented. The results contradict those in high-risk populations, but are consistent with more recent population-based studies that find no associations.In the wider population, the investigated link does not appear to be as clearly demonstrable as in populations with high traumatic burden, such as veterans, which seems reassuring news given that LTE are risk factors for numerous comorbidities that could then play a role in the development of the cognitive changes.

Midlife stress-related exhaustion and dementia incidence: a longitudinal study over 50 years in women

BACKGROUNDS

Cognitive problems are common symptoms among individuals with stress-related exhaustion. It is still unknown whether these individuals are at a higher risk of developing dementia later. This study aims to examine the relationship between midlife stress-related exhaustion and dementia incidence.

METHODS

A population sample of 777 women (aged 38, 46, 50 and 54 years) without dementia at baseline was followed over 50 years, from 1968 to 2019. Stress-related exhaustion was based on information from the psychiatric examination in 1968/69. Information on dementia incidence between 1968 and 2019 was obtained from neuropsychiatric examinations, key-informant interviews, and hospital registry. Dementia was diagnosed according to the DSM-III-R criteria. A subgroup of non-demented women (n = 284) was examined for cognitive functions by the Gottfries-Bråne-Steen scale 24 years after baseline.

RESULTS

Stress-related exhaustion in midlife was associated with higher risk for development of dementia before age 75 (Hazard ratio and 95% confidence interval: 2.95 and 1.35-6.44). The association remained after adjustment for age, major depression, and anxiety disorder. Mean age of dementia onset was younger for women with stress-related exhaustion than women without stress (mean ± SD, 76 ± 9 vs. 82 ± 8 . p = 0.009). Women with stress-related exhaustion in midlife still showed more cognitive impairments 24 years later compared with women without stress (Odds ratio and 95% confidence interval: 2.64 and 1.15-6.06).

CONCLUSIONS

We found that women with stress-related exhaustion in midlife were at a higher risk to develop dementia at relatively younger age. These women showed persistently lower cognitive functions over years even without dementia. Present study results need to be interpreted with caution due to small sample size and should be confirmed in future studies with larger sample size. Our study findings may imply the importance of long-term follow-up regarding cognitive function among individuals with stress-related exhaustion.

Experimental laboratory models as tools for understanding modifiable dementia risk

Experimental laboratory research has an important role to play in dementia prevention. Mechanisms underlying modifiable risk factors for dementia are promising targets for dementia prevention but are difficult to investigate in human populations due to technological constraints and confounds. Therefore, controlled laboratory experiments in models such as transgenic rodents, invertebrates and in vitro cultured cells are increasingly used to investigate dementia risk factors and test strategies which target them to prevent dementia. This review provides an overview of experimental research into 15 established and putative modifiable dementia risk factors: less early-life education, hearing loss, depression, social isolation, life stress, hypertension, obesity, diabetes, physical inactivity, heavy alcohol use, smoking, air pollution, anesthetic exposure, traumatic brain injury, and disordered sleep. It explores how experimental models have been, and can be, used to address questions about modifiable dementia risk and prevention that cannot readily be addressed in human studies. HIGHLIGHTS: Modifiable dementia risk factors are promising targets for dementia prevention. Interrogation of mechanisms underlying dementia risk is difficult in human populations. Studies using diverse experimental models are revealing modifiable dementia risk mechanisms. We review experimental research into 15 modifiable dementia risk factors. Laboratory science can contribute uniquely to dementia prevention.

Occupational stress and musculoskeletal disorders in firefighters: the mediating effect of depression and job burnout

The firefighting profession carries a heightened risk of musculoskeletal disorders. A firefighter's job is physically demanding and includes activities such as running, climbing, dragging, and lifting. Often, these tasks are unpredictable, performed in harsh environments, and have been found to cause psychological stress. The purpose of this study was to investigate the effects of occupational stress on work-related musculoskeletal disorders (WRMSD) in firefighters. In addition, the mediating effects of depression and job burnout on proposed relationships were examined. Data informing this study were collected using a survey questionnaire. The survey questionnaire included the Beck Depression Inventory, the Center for Epidemiological Studies Depression Scale (CES-D), the Maslach Burnout Inventory, the Post Traumatic Stress Disorder Inventory (PCL), and the Nordic Musculoskeletal Questionnaire. Collected data were analyzed using structural equation modeling approach in AMOS. The results of the 2339 responding firefighters suggest that work related stress is positively related to WRMSDs in firefighters and can lead to musculoskeletal symptoms through four paths, being emotional exhaustion, personal accomplishment, CES-D total score, and depersonalization. Through depersonalization, job stress had the most significant impact on musculoskeletal symptoms (coefficient = 0.053). Furthermore, the results showed that post-traumatic stress disorders (PTSD) can affect musculoskeletal symptoms through ten paths, again through depersonalization, PTSD had the most significant impact on musculoskeletal symptoms (coefficient = 0.141). The results of this study suggest that organizations should design interventions and policies to prevent and manage occupational stress, depression, and job burnout to negate its undesired consequences on firefighters' health (i.e. WRMSD).