Depression in Alzheimer's Disease: Epidemiology, Mechanisms, and Treatment.

Depression and Alzheimer's disease (AD) are substantial public health concerns. In the past decades, a link between the 2 disease entities has received extensive acknowledgment, yet the complex nature of this relationship demands further clarification. Some evidence indicates that midlife depression may be an AD risk factor, while a chronic course of depression in late life may be a precursor to or symptom of dementia. Recently, multiple pathophysiological mechanisms have been proposed to underlie the bidirectional relationship between depression and AD, including genetic predisposition, immune dysregulation, accumulation of AD-related biomarkers (e.g., amyloid-ß and tau), and alterations in brain structure. Accordingly, numerous therapeutic approaches, such as pharmacology treatments, psychotherapy, and lifestyle interventions, have been suggested as potential means of interfering with these pathways. However, the current literature on this topic remains fragmented and lacks a comprehensive review characterizing the association between depression and AD. In this review, we aim to address these gaps by providing an overview of the co-occurrence and temporal relationship between depression and AD, as well as exploring their underlying mechanisms. We also examine the current therapeutic regimens for depression and their implications for AD management and outline key challenges facing the field.

Occupational characteristics and incident anxiety and depression: A prospective cohort study of 206,790 participants.

BACKGROUND: This study aimed to analyze the impact of a wide spectrum of occupational characteristics on the incidence of anxiety and depression, and to determine the features affecting adaptation to specific characteristics. METHODS: Participants in paid employment or self-employed at baseline in UKB were included, with occupational characteristics extracted from O*NET. Cox-proportional-hazard models were conducted in the main analyses and subgroup analyses. RESULTS: Direct work with the public and exposure to disease/infections were first time demonstrated to be risk factors for both anxiety and depression, along with occupations involving more physical activities and dealing with unpleasant/physically aggressive people. Protective factors for both: time spent sitting, communication, decision making, creativity and reasoning, and responsibility in work. Protective factors for anxiety only: Coordinating/leading, fluency of ideas, originality, problem sensitivity, decision latitude, and time pressure. Risk factor for depression only: Exposure to contaminants. Females were found more sensitive to dealing with unpleasant/physically aggressive people. The impact of exposure to disease/infections was more significant among those with lower education levels. Those with BMI over 24 were more sensitive to the risk factors. LIMITATIONS: The short-term effect of the above exposures remained unclear. The scores of occupational characteristics were based on self-reported questionnaires. There was the potential for undiagnosed anxiety or depression events. The participants included only those aged from 40 to 69. Participants included in this cohort were mainly White British. CONCLUSIONS: Our findings advocate closer monitoring of the mental health of workers with risk work-related factors.

Identification of novel drug targets for the risk and prognosis of COVID-19.

Background: Since the epidemic continues, there is a pressing need to improve our understanding of coronavirus disease 2019 (COVID-19). Mendelian randomization (MR) studies provide us with a method to explore the causality between circulating proteins and COVID-19 susceptibility and severity. We aim to find new perspectives on the pathological mechanism of the disease and possible drug targets for treatment based on this study. Methods: We conducted a phenome-wide MR study to prioritize circulating proteins causally associated with COVID-19 susceptibility, which was defined as "patients tested positive for COVID-19 vs. population controls", and severity, which was defined as "patients hospitalized with COVID-19 vs. population controls". And we repeated the analysis for different definition of COVID-19 susceptibility, severity and control groups. Results: Association of three circulating proteins with COVID-19 susceptibility and severity were demonstrated via our study. C-C motif chemokine 4 (OR =1.887, 95% CI: 1.608-2.165, P=8.04×10-6) and 2'-5'-oligoadenylate synthase 1 (OR =0.511, 95% CI: 0.266-0.757, P=8.51×10-8) were found respectively positively and negatively correlated with increased COVID-19 severity. Tissue factor, contrary to previous studies, was found associated with decreased COVID-19 susceptibility (OR =0.667, 95% CI: 0.484-0.850, P=1.47×10-5) and decreased COVID-19 severity (OR =0.459, 95% CI: 0.132-0.786, P=3.01×10-6). Conclusions: Genetic evidence supports C-C motif chemokine 4 as a risk factor for COVID-19 severity, and 2'-5'-oligoadenylate synthase 1 as a protective factor for COVID-19 severity. The causal association between tissue factor and COVID-19 is contrary to the previous studies, needing further analyses. Further research is warranted to assess the viability of C-C motif chemokine 4 and 2'-5'-oligoadenylate synthase 1 as well as their downstream pathways as drug targets for anti-inflammatory and anti-virus treatment in severe cases.