Assessing the Dynamics of the Mental Health Apple and Android App Marketplaces.

Barriers to mental health care, including stigma, costs, and mental health professional shortages, have been exacerbated by the COVID-19 pandemic. Smartphone apps have the potential to increase scalability and improve access to mental health information, support, and interventions. However, evaluating these apps and selecting ones for use in care remain challenging, especially as apps are often updating and changing. Recommending apps requires knowledge of how stable apps are as the experience of one user several months ago may or may not be the same. A sample of 347 apps of the 650 apps on the M-health Index and Navigation Database (MIND) https://mindapps.org were reviewed between September 1, 2021, and January 5, 2022. Apps were selected by time since their last review, with updates occurring on average approximately 4 months from the last review. Eleven trained app evaluators reviewed apps across 105 evaluation criteria in 9 categories. Results were compared to initial ratings, identifying the changes that occurred. The average app updates every 433 days, though 19% were updated in the last 3 months and some nearly weekly. Changes in privacy and features made up the highest percentage of changes, both at 38%. The most frequently observed privacy-related change was increased privacy policy reading level. Functionality parameters changed in 28% of apps. The most common functionality change was the removal of an accessibility feature. Clinical foundations changed in 18% of apps and 9% added supporting studies. Cost structure changed in 17% of apps, with 10% adding a fee for use of the app. Engagement features changed in 17% of the apps, with additions and removals of validated assessments or screeners most common. The dynamic nature of the app stores is reflected in app privacy, features, and functionality. These changes, reflected by the increased reading levels required to understand privacy policies, the decrease in accessibility features, and the additions of fees to access mobile apps, reflect the need to constantly review apps and understand how they are evolving. Patient and clinicians should use the most recent and updated possible when evaluating apps.