BackgroundExecutive 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.MethodA 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.ResultsA 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.ConclusionsSelf-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.