Comparative efficacy of PsyPills and OCAT mobile psychological interventions in reducing depressive, anxiety and stress symptoms: A blinded randomized clinical trial.

Background: Digital applications, such as in smartphone apps format, have shown high suggestive evidence for their efficacy in reducing general distress, but rigorous studies of their efficacy in symptom change and the mechanisms involved are still needed.

Methods: In the current multi-arm parallel-group randomized trial, participants aged 18-65 with smartphone access were recruited through social media. They were randomly assigned to two app interventions (PsyPills and OCAT) or an active placebo group (shamOCAT). The primary outcome was psychological distress measured up to one month.

Results: A total of 229 participants from diverse regional and demographic groups of the general population of Romania were randomly allocated into the three groups (PsyPills n = 80; OCAT n = 70; shamOCAT n = 79) and included in intention-to-treat analyses. Both the PsyPills (MD = -522; 95%CI = -10.00 to -0.44; d = 0.48) and OCAT (MD = -6.30; 95%CI = -11.39 to -1.21; d = 0.58) reduced significantly, with medium effect sizes, the psychological distress levels compared with the control group at follow-up. For the separate outcomes, only PsyPills showed significant medium reduction effects for anxiety symptoms (MD = -2.17; 95%CI = -3.83 to -0.50; d = -0.60), while OCAT showed reduction effects of small size for depression (MD = -1.50 (95%CI = -3.53 to 0.54, d = -0.34), that was however statistically nonsignificant.

Limitations: We registered high attrition and low adherence rates. Also, lower-than-planned effects might have been statistically underpowered to detect.

Conclusion: The results support the high potential of both apps as scalable tools to provide low-intensity self-guided interventions for common psychological problems in the general population and expand opportunities for further research (e.g., confirm and capitulate on the differential effects).