A specialized iPhone app was used to block internet access, recording any time that the feature was disabled.

In numbers, nearly all the participants — 91 percent — improved on at least one of the three outcomes, while around three-quarters reported better mental health by the end.

The findings even suggest that the intervention had a stronger effect on depression symptoms than antidepressants, and was roughly on par with cognitive behavioral therapy.

What's driving all this? Ward suggests that the simplest explanation is that the experiment forced participants to spend more time doing fulfilling things in the real world.