"Money Doesn't Buy You Happiness": Negative Consequences of Using the Freemium Model for Mental Health Apps.

As global rates of anxiety and depression increase, we observe millions of downloads of mobile apps addressing mental health that adopt 'freemium' charging models offering complex combinations of free and paid features. We explore potentially negative outcomes of deploying such freemium designs to vulnerable MH populations. We assess outcomes for 41 frequently downloaded mental health apps, by combining thematic analysis of 41K user reviews with audits to validate app descriptions and reviews. We propose a new analytic framework identifying three types of negative outcomes for freemium deployments: first vulnerable users currently experiencing crises may feel pressure to download unhelpful or costly apps. Second unintuitive descriptions of complex apps can lead to inappropriate treatments and expensive subscriptions. Third, limited duration offers may result in incomplete treatments or unexpected charges. We discuss ethical considerations and broader HCI consequences. We describe implications for mental health app design, including the need for greater transparency around free versus paid features, and propose new approaches to provide vulnerable users with validated information about these commonly downloaded apps.