JMIR Publications

ABSTRACT

Background:

Repetitive negative thinking (RNT) is a key transdiagnostic mechanism underpinning depression and anxiety. Using ‘just-in-time adaptive interventions’ via smartphones may disrupt RNT in real-time, providing targeted and personalized intervention.

Objective:

This pilot randomized controlled trial evaluated the feasibility, acceptability and preliminary clinical outcomes and mechanisms of Mello – a fully automated, personalized, transdiagnostic, mechanistic smartphone intervention targeting RNT in young people with depression and anxiety.

Methods:

Participants with heightened depression, anxiety and RNT, were recruited online via social media and randomized to receive Mello or a non-active control over a six-week intervention period. Assessments were completed online via zoom sessions at baseline, and 3- and 6-weeks post-baseline.

Results:

Findings supported feasibility and acceptability, with high rates of recruitment (N = 55), uptake (86% of eligible participants), and retention (95% at 6-weeks). Engagement was high with 90% and 59% of participants in the Mello condition still using the app during the third and sixth weeks respectively. Greater reductions in depression (Cohen’s d=0.50), anxiety (Cohen’s d=0.61) and RNT (Cohen’s d=0.87) were observed for Mello users versus control. Mediation analyses suggested that changes in depression and anxiety were accounted for by changes in RNT.

Conclusions:

Results indicate that mechanistic, targeted and real-time technology-based solutions may provide scalable and effective interventions that advance treatment of youth mental ill-health. Clinical Trial: Australian New Zealand Clinical Trials Registry ACTRN12621001701819; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=362117