Researchers found no correlation between consumer ratings and privacy scores in a review of mental health apps.

The study, published in JAMA Network Open, assessed nearly 580 mental health apps for accessibility, privacy and security, interoperability, features offered, and how users input data and receive feedback.

It found 77% of the apps studied featured a privacy policy, but on average those policies were written at a 12th grade reading comprehension level. The study noted 44% shared health information with third parties. 

There was no correlation between star ratings on the Apple App Store or the Google Play Store and privacy scores, though the number of app downloads from Google's store weakly correlated with privacy.

Of the apps studied, all were available in English, but only 18% were also offered in Spanish. More than half offered at least one accessibility feature, like text size adjustment or text-to-speech or speech-to-text abilities, and 65% could function without an internet connection. Though 88% were free to download, only 39% were completely free, with others including in-app purchases to subscription plans for full functionality. 

Only 15% of the apps included a feasibility or efficacy study, though the analysis didn't evaluate the quality of those studies. Some 30% of the apps allowed users to export or email their data, but only 2% could be integrated with an EHR. 

The most common features offered by the mental health apps were psychoeducation, followed by goal setting and habit forming, and then mindfulness. However, few apps offered biofeedback using sensor data, Acceptance and Commitment Therapy (2%) and Dialectical Behavioral Therapy.

"These findings suggest that apps on the marketplace offer overlapping features, and metrics such as star ratings or the number of downloads may not provide adequate information about the privacy or efficacy of mental health apps," the study's authors wrote.

WHY IT MATTERS

Researchers noted some limitations to the study, since they did not evaluate app quality or the science behind the apps. They also only analyzed apps that cost $10 or less, so more expensive offerings could provide different tools. 

But they argue the current regulation landscape for mental health apps leaves patients and clinicians to evaluate apps with little formal support. Many apps lacked accessibility features, and few were offered in Spanish, giving some users limited options. Apps that offer support for higher-acuity conditions were also less common. For example, only 13 were designed for people with schizophrenia. 

Though it's positive that most of the apps had a privacy policy, they might be hard to read for many users. Since app store ratings weren't correlated with privacy scores, they might not be aware of privacy issues when they choose apps as well. 

However, since there are a large number of free mental health apps and many offer similar features, clinicians and patients can be picky when making decisions.

"The findings of this cross-sectional study suggest that the current app marketplaces lack diversity in their offerings and fail to implement potentially high-impact features," the study's authors wrote. "Another challenge to the app space is that easily accessible metrics like star ratings fail to consider privacy capabilities. Thus, clinicians and patients must discern apps beyond such measures to ensure the discovery of apps that both fit their unique needs and protect their privacy."