Family physicians in Britain are increasingly prescribing art classes, gardening clubs and walking groups — as an alternative to pills — to patients with mental health challenges. The practice, known as social prescribing, is covered by the U.K.'s National Health Service or NHS and is geared toward people with mental health challenges described as mild or moderate. "What we're looking at is non-medical solutions — where appropriate — for people that can often be more transformative than just giving them medication, which doesn't always get to the root of the cause," says Marie Polley, founder of the Social Prescribing Network, a group of health professionals involved with using the method. "Within the NHS, we have general practitioners who are all recognizing that people are coming back to see them over and…