Kyoto, Japan -- Smartphones may often feel like a source of stress, feeding us an endless stream of bad news and social comparison. But what if they could also be the solution?
A team of researchers from Kyoto University believes they can be. The team has developed a smartphone app that delivers core techniques of cognitive-behavioral therapy (CBT) -- a proven treatment for depression and anxiety -- straight into the hands of users, and tested it in the largest-ever individually randomized trial of its kind.
Their resilience training app, called RESiLIENT, was tested on nearly 4,000 adults across Japan experiencing subthreshold depression -- a form of low-level but persistent depressive symptoms that doesn’t meet criteria for major depressive disorder but can still be debilitating. This condition affects an estimated 11% of people worldwide and often goes untreated.
"CBT is highly effective, but delivering it at scale has always been a challenge," says lead author Professor Toshiaki Furukawa. "Our goal was to make these skills available to anyone, anywhere."
The app teaches five fundamental CBT skills: behavioral activation, cognitive restructuring, problem solving, assertion training, and techniques for managing insomnia. Participants used the app over six weeks and were followed for six months. The study included three control groups, one of which used a health information app, another a self-check app, and the third no treatment at all (waiting list).
Statistical analysis indicated that six weeks of learning was effective for up to 26 weeks, and in treating not only subthreshold depression but also anxiety and insomnia. The effect of the app compared favorably to the effect of antidepressants. Importantly, use of the app did not result in any serious adverse effects.
"We can use this knowledge to personalize and optimize which skills to administer for each individual to match their needs and characteristics," says Furukawa. "This opens the door to optimized, long-term support."
The research team is now preparing a platform to administer the best interventions for each individual over the course of 12 months, which they hope will continue to provide the necessary skills to minimize the total burden of depression.
As the world continues to grapple with a mental health crisis, this study offers hope that the very devices often blamed for contributing to emotional distress might also become powerful tools for healing.

Related link
【DOI】
https://doi.org/10.1038/s41591-025-03639-1
Toshi A. Furukawa, Aran Tajika, Rie Toyomoto, Masatsugu Sakata, Yan Luo, Masaru Horikoshi, Tatsuo Akechi, Norito Kawakami, Takeo Nakayama, Naoki Kondo, Shingo Fukuma, Ronald C. Kessler, Helen Christensen, Alexis Whitton, Inbal Nahum-Shani, Wolfgang Lutz, Pim Cuijpers, James M. S. Wason, Hisashi Noma (2025). Cognitive behavioral therapy skills via a smartphone app for subthreshold depression among adults in the community: the RESiLIENT randomized controlled trial. Nature Medicine.