There are now thousands of meditation apps available worldwide, the top 10 of which have been collectively downloaded more than 300 million times. What's more, early work on these digital meditation platforms shows that even relatively brief usage can lead to benefits, from reduced depression, anxiety, and stress to improved insomnia symptoms.

"Meditation apps, such as Calm and Headspace, have been enormously popular in the commercial market," said J. David Creswell, a health psychologist at Carnegie Mellon University and lead author of a review paper on meditation apps, published today in the journal American Psychologist. "What they're doing now is not only engaging millions of users every day, but they're also creating new scientific opportunities and challenges."

One huge boon provided by meditation apps for users is access.

"You can imagine a farmer in rural Nebraska not having many available opportunities to go to traditional group-based meditation programs, and now they have an app in their pocket which is available 24/7," said Creswell, who is the William S. Dietrich II Professor in Psychology and Neuroscience.

Meditation apps also provide scientists with opportunities to scale up their research.

"Historically, I might bring 300 irritable bowel syndrome patients into my lab and study the impacts of meditation on pain management," said Creswell. "But now I'm thinking, how do we harness the capacity of meditation apps and wearable health sensors to study 30,000 irritable bowel syndrome patients across the world?"

Combined with products that measure heart rate and sleep patterns, such as Fitbit and the Apple Watch, meditation apps now also have the capacity to incorporate biometrics into meditation practices like never before.

The biggest takeaway, though, is that meditation apps are fundamentally changing the way these practices are distributed to the general public. Scientific studies of use patterns show that meditation apps account for 96 percent of overall users in the mental health app marketplace.

"Meditation apps dominate the mental health app market," said Creswell. "And this paper is really the first to lay out the new normal and challenge researchers and tech developers to think in new ways about the disruptive nature of these apps and their reach."

Meditation apps challenge users to train their minds, in small initial training doses

As with in-person meditation training, meditation apps start by meeting users where they are. Introductory courses may focus on breathing or mindfulness, but they tend to do so in small doses, the merits of which are still being debated.

According to the data, just 10 to 21 minutes of meditation app exercises done three times a week is enough to see measurable results.

"Of course, that looks really different from the daily meditation practice you might get within an in-person group-based meditation program, which might be 30 to 45 minutes a day," said Creswell.

The a la carte nature of meditation through a smartphone app may appeal to those pressed for time or without the budget for in-person coaching sessions. Users may also find it comforting to know that they have access to guided meditation on-demand, rather than at scheduled places, days, and times.

"Maybe you're waiting in line at Starbucks, and you've got three minutes to do a brief check-in mindfulness training practice," said Creswell.

Finally, as meditation apps continue to evolve, Creswell believes integration of AI, such as meditation-guiding chat-bots, will only become more common, and this will offer the option of even more personalization. This could mark an important development for meditation adoption at large, as offerings go from one-size-fits all group classes to training sessions tailored to the individual.

"People use meditation for different things, and there's a big difference between someone looking to optimize their free-throw shooting performance and someone trying to alleviate chronic pain," said Creswell, who has trained Olympic athletes in the past.

The elephant in the room

Of course, with new technology comes new challenges, and for meditation apps, continued engagement remains a huge problem.

"The engagement problem is not specific to meditation apps," said Creswell. "But the numbers are really sobering. Ninety-five percent of participants who download a meditation app aren't using it after 30 days."

If the meditation app industry is going to succeed, it will need to find ways to keep its users engaged, as apps like Duolingo have. But overall, Creswell said the market demand is clearly there.

"People are suffering right now. There are just unbelievably high levels of stress and loneliness in the world, and these tools have tremendous potential to help," he said.

"I don't think there is ever going to be a complete replacement for a good, in-person meditation group or teacher," said Creswell. "But I think meditation apps are a great first step for anyone who wants to dip their toes in and start training up their mindfulness skills. The initial studies show that these meditation apps help with symptom relief and even reduce stress biomarkers."