Abstract
BACKGROUND: Executive dysfunction and depression are common among ICU survivors, yet the mechanisms linking these two factors remain poorly understood. Self-confidence has been implicated as a key mediator in the relationship between cognitive impairments and mental health outcomes. This study aimed to explore the mediating role of self-confidence in the association between executive functioning and depression in ICU survivors. METHOD: A provisional questionnaire was used in a cross-sectional study to assess quality of life in 395 adult ICU survivors, each with a minimum 72-h stay at one of three ICUs at a Swedish university hospital, six months to three years post-discharge. Responses to questions on executive function, self-confidence, and depression were analysed. Structural equation modelling and confirmatory factor analysis were employed to examine the mediating effect of self-confidence on the relationship between executive function and depression. Model fit was evaluated using established indicators. Reliability of the measures was assessed using McDonald's Omega and Cronbach's Alpha. RESULTS: A significant positive correlation was found between depressive symptoms and both diminished self-confidence (r = 0.80, p < 0.001) and poorer executive function (r = 0.55, p < 0.001). Additionally, a correlation was observed between reduced self-confidence and compromised executive function (r = 0.62, p < 0.001). Age was negatively associated with depression, self-confidence, and executive function, while male gender was positively correlated with higher self-confidence. Mediation analysis revealed that the effect of impaired executive function on depressive symptoms was fully mediated by diminished self-confidence (B = 0.45; 95% CI 0.34-0.59). The direct effect of executive function on depression became non-significant when self-confidence was included in the model (B = 0.07, p = 0.18), suggesting complete mediation. The overall model fit was satisfactory (CFI = 0.962; RMSEA = 0.075), highlighting the robustness of the mediation pathway. CONCLUSIONS: Self-confidence mediates the relationship between executive function and depression among ICU survivors. Interventions aimed at enhancing self-confidence could mitigate depressive symptoms in the ICU survivor population. Longitudinal studies are needed to confirm these findings and further explore the causal pathways involved. Trial registration ClinicalTrials.gov Ref# NCT02767180; Registered 28 April 2016.