“Frailty and depression: a comprehensive perspective on their role in adverse health outcomes”

Introduction: Frailty and the depression are two distinct, yet interrelated conditions commonly observed in the elderly population, whose prevalences rise alongside the ageing process. Although both conditions have been shown to be risk factors for adverse outcomes, they have been treated separately, omitting their interrelationship. Aims: To evaluate the associations between frailty-depression categories, and adverse events through a prospective, population-based cohort design using data from 1,412 individuals in the Toledo Study of Healthy Ageing. Methods: The depressive symptoms was evaluated using the Geriatric Depression Scale questionnaire, and frailty was assessed through both the Frailty Phenotype and the 5 item Frailty Trait Scale (FTS5). The associations of frailty and the depressive symptoms, both as independent factors and in combination, with adverse events were assessed using a Cox proportional hazards regression model for mortality analysis and logistic regression for incident and worsening disability. Additionally, analyses stratified by sex were performed. Results: We found that when both conditions were treated as independent, each was associated with adverse events. However, when the resulting categories were analyzed, having depressive symptoms increased the risk of adverse events only in the presence of frailty, specifically in prefrail and frail categories of the Frailty Phenotype and in the frail category of the FTS5. Conclusions: This study suggests a possible synergistic effect between the studied factors when frailty is affected. Similar synergistic effects may also exist with other clinical conditions, so that obtaining a more accurate risk of adverse outcomes would be better achieved by using such resulting categories.