In digital mental health, success is often judged by downloads and retention. While these are important, it’s an incomplete story. The question that really matters is: are young people building knowledge and skills that improve their wellbeing?
Published in Frontiers in Psychiatry: Digital Mental Health, our paper on developing a theory of change for Soluna marks a significant contribution to more systematic approaches to designing, implementing, and evaluating digital mental health platforms. It outlines practical steps for building a theory of change in an industry setting, while keeping young people and diverse stakeholders integral throughout.
Why a theory of change matters in digital mental health
A theory of change is a structured framework that maps how and why an intervention creates change.
In the digital space, mental health apps are too often seen as products, rather than interventions. A theory of change can bridge this gap, redirecting attention to outcomes that matter. It can shape how we build an app using behavioral science, support implementation, and create the foundation for robust evaluation.
How we build one
Using Soluna as a practical case study, we outline a three-phase process to build a theory of change in a real-world, industry context. In doing so, we drew on a range of diverse and engaging methods to ensure the process was inclusive and meaningful.
We adopted a convergent mixed methods design using an iterative approach, where insights from one phase influenced the next.
- •
First, young people completed a digital diary to provide feedback on the proof-of-concept app
- •
Second, service staff and external experts engaged in a workshop series to map the pathways from the intervention to outcomes, guided by existing behavioral change models
- •
Third, young people provided feedback on the theory of change framework via an express media survey
As well as the strengths of our approach, the paper also reflects on our lessons learned, such as the importance of translating complex ideas into accessible language to empower staff to apply the framework. This creates a shared understanding across teams and keeps meaningful outcomes at the center.
This methodology demonstrates that developing a theory of change in the digital mental health industry is both feasible and highly beneficial.
Soluna’s Journey to Change
The outcome of this process was a theory of change for Soluna, named by youth as Soluna’s Journey to Change. This framework shows how each of Soluna’s features contributes to meaningful change for young people. For example, Soluna’s pre-moderated peer community provides a safe and supportive space for young people to connect with like-minded others.
Through the peer community, users develop a sense of relatedness, which contributes to increased self-determination. Together, these gains strengthen psychological flexibility. Greater flexibility supports healthier relationships and more vibrant, productive communities.
Looking ahead
A theory of change is not a one-off exercise, but an evolving framework. It should be revised at key points in an intervention’s lifecycle - from when it’s first implemented to when it scales.
For Soluna, this means revisiting and adapting the framework in response to user experience, new data, evolving context, and the demands of scaling.
For the wider digital mental health field, it means embracing a theory of change as a living tool - one that ensures interventions stay grounded in evidence, responsive to what young people need, and focused on the outcomes that matter most.
Read the full article here