Promoting Psychological Resilience and Well-Being in Youth With a Smartphone-Based Ecological Momentary mHealth Intervention: Secondary Analysis of a Micro-Randomized Trial (Preprint)

BACKGROUND Young individuals have been facing a multitude of crises in the past years, which may be associated with negative mental health outcomes. Interventions to mitigate the negative impact and promote mental well-being are necessary. Ecological momentary interventions (EMIs) may be a promising tool for promoting mental well-being as they allow to target resilience and other protective factors in daily life. OBJECTIVE In this secondary analysis of a micro-randomized trial, we explored proximal effects of a compassion-focused smartphone-based digital training for young people applying principles and techniques of EMI (the AI4U training) on momentary outcomes of mental well-being. METHODS Participants aged 14 to 25 years completed up to six ecological momentary assessments (EMA) per day to measure their momentary mental well-being (ie, positive affect, negative affect, and stress) during the 30-day AI4U training phase. Some EMA prompts triggered EMI components to promote their momentary resilience and well-being. Proximal effects of initiating EMI components on outcomes assessed at the next time point were analyzed using multilevel modelling. Moderation and mediation analyses were applied to investigate the potential moderating effect of momentary affect and stress at the time of EMI initiation and to explore change in momentary resilience as a mediator of the effect of EMI initiation on changes in momentary affect and stress. RESULTS 170 individuals completed 13059 EMA prompts and initiated 6667 EMI components. No evidence was found that momentary outcomes of mental well-being at a time point differed depending on whether an EMI component was initiated at the previous time point vs. when no EMI component was initiated (positive affect: b=0.00, CI -0.04 to 0.04; negative affect: b=-0.01, CI -0.05 to 0.03; stress: b=0.01, CI -0.03 to 0.05). There was no strong difference in the magnitude of this effect when momentary mental well-being at the time of EMI initiation was high vs. low (positive affect: b=0.07, 95% CI=-0.00 to 0.15; negative affect: b=-0.01, CI=-0.09 to 0.06; stress: b=0.07, CI=-0.01 to 0.15). Changes in momentary resilience did not mediate the effect of EMI component initiation on changes in momentary mental well-being (positive affect: b=0.01, CI=-0.01 to 0.02; negative affect: b=0.00, CI=-0.01 to 0.00; stress: b=0.00; CI=0.00 to 0.00). CONCLUSIONS This secondary analysis investigated potential mechanisms of how a digital training leads to long-term improvement of distal outcomes. The analysis contributes to the research in the field by serving as a basis for future investigations on the momentary effects of EMI components.