Katie grew up in Devon and carried the same close group of friends with her from school through to adulthood. They were always together, laughing and enjoying themselves.

Then, after she fled an abusive relationship in her early twenties, Katie started to get unwell - she felt paranoid and anxious all the time. "Suddenly a lot my friends just dropped me - just like that," she explains. "It was horrible. They were my life."

But there are friends who have stuck by Katie. "My best friend, she's always calling me, sending me little notes. She's great."