Conclusions
depression, TG, anxiety
The results of this pilot RCT suggest that the Mello app is feasible, acceptable, and potentially clinically effective. Large and significant reductions in RNT scores were found, which may explain the effects of Mello on anxiety and depression. These findings support ongoing research and development, with a focus on enhancing personalization using machine learning, conducting a larger RCT to establish efficacy and mechanisms of action, evaluating cost-effectiveness, and ultimately scaling the intervention to ensure that all young people have permanent access to Mello.The authors would like to acknowledge the young people who dedicated their time to participating in this trial and the young people and clinicians who provided input into the design of Mello, including the MOST team at Orygen Digital. Finally, the authors would like to acknowledge the significant role of Sally Coldham, Jessi Malouf and James Gallichio, and Paul Hoskins and Nick Davis from Everyhow, in the design and development of Mello, as well as Telstra Foundation (particularly Natalie Falzon) for their generous support and guidance.The development of the Mello app and this research trial were funded by the Telstra Foundation Tech-4-Good Challenge, in support of Everyhow. This work was also supported by a Wellcome Trust Active Ingredients project on Reducing Repetitive Negative Thinking awarded to IB. IB is supported by a National Health and Medical Research Council (NHMRC) Investigator Grant (#2017876). MA-J is supported by an NHMRC Investigator Grant (#1177235) and a Dame Kate Campbell Fellowship from the University of Melbourne.Authors' Contributions: MA-J acquired funding along with TG and SD. IB led the design and development of the Mello intervention and the conceptualization and methodology of this trial. CA led project administration and investigation and supervised EC to collect the data, with oversight from MA-J. NC and SO conducted the formal analysis. IB and CA wrote the original draft of the manuscript. All authors reviewed and edited the manuscript.Conflicts of Interest: None declared.Participant information and consent form.Description of therapy activities.CONSORT-eHEALTH checklist (V 1.6.1).Ratings of therapy activity helpfulness.Digital Working Alliance Inventory results.Engagement correlations.Secondary outcome results.