Accessing mental health care has long been difficult  and the pandemic has further increased the strain. And there are thousands of mental health apps — about 20,000 and counting — designed to tackle the problem. They range from mood trackers, guided mindfulness exercises and apps with chatbots that teach coping skills. Spending on them has grown quickly since 2019 and is predicted to reach about $500 million this year, according to a report from Deloitte. But not all these apps are backed by science. Stephen Schueller is a professor at UC Irvine and the executive director of One Mind PsyberGuide, which provides expert ratings for hundreds of wellness apps. He talked to host Meghan McCarty Carino about how the apps are rated.