The Effectiveness and Mechanisms of Action of App-based Interventions for Improving Mental Health and Workplace Wellbeing: A Randomised Controlled Trial (Preprint)

BACKGROUND Depression is the most common mental health disorder worldwide and frequently leads to workplace absences. As face-to-face treatment can be difficult to access app-based interventions are a popular solution, although their effectiveness in working populations and mechanisms of action are unclear. Deficits in executive functioning (EF) may contribute to the onset and maintenance of depression, and EF training is proposed to improve symptoms by enhancing EF. Responders to cognitive behavioural therapy (CBT) show improvements in EF, suggesting this may be one mechanism of action. OBJECTIVE This study investigated the effectiveness of app-based interventions (EF- or CBT-based) in reducing depressive and anxious symptoms, and improving workplace wellbeing, and whether changes in EF mediated improvements. METHODS 228 participants (147 female) with mild to moderate depression and anxiety were randomly assigned to either a waitlist control group, or to use an EF training app or a self-paced CBT app. Participants completed measures of depressive symptoms, anxious symptoms and workplace wellbeing at baseline, after the 4-week intervention period, and at 12-week follow-up. RESULTS EF training reduced anxiety and depressive symptoms at follow-up, but not at post-intervention, and did not affect workplace wellbeing. There were no reductions in depressive or anxiety symptoms in the self-guided CBT group, though workplace wellbeing was improved post-intervention and at follow-up. Improvements in EF did not mediate intervention-related changes in symptoms or workplace wellbeing. CONCLUSIONS These results suggest app-based EF training may be effective at managing symptoms of anxiety and depression in a working population, whilst using self-guided CBT apps may improve workplace wellbeing. However, EF did not appear to be a mechanism of action of either intervention. CLINICALTRIAL The study was pre-registered on the Open Science Framework: https://osf.io/zsncj