Quantifying App Store Dynamics: Longitudinal Tracking of Mental Health Apps

Area of Science:

• Digital mental health
• Mobile health applications
• App store analytics

Background:

• Mobile health (mHealth) apps offer accessible mental health support outside clinical settings.
• Commercial app stores face challenges like app turnover and lack of evidence-based content.

Purpose of the Study:

• Quantify the longevity and turnover rate of mental health apps on Android and iOS.
• Assess the clinical relevance and longevity of these apps.
• Determine the proportion of clinically relevant apps claiming effectiveness.

Main Methods:

• Daily searches of iTunes (iOS) and Google Play (Android) for mental health apps over 9 months.
• Analysis of app availability, clinical relevance, and claims of effectiveness.
• Subgroup analyses included search ranking, user ratings, and download counts.

Main Results:

• Android search results showed significant daily changes (50% turnover in 115-195 days).
• iOS search results were more stable; 75% of Android and 90% of iOS apps remained available.
• Only 35.3% of depression apps were clinically relevant, with 2.6% claiming effectiveness and only 3 citing studies.

Conclusions:

• The mental health app market is highly volatile, with clinically relevant depression apps becoming unavailable frequently.
• This instability complicates access for consumers and clinicians and hinders research into app efficacy.
• Urgent need for strategies to ensure the availability and reliability of evidence-based mental health apps.