Gemma Correll has suffered from anxiety and depression disorders since childhood, and at 16 she discovered a magical elixir that promised to make her feel better. In this extract from her new book, she shows how that promise was broken

In 2018, I was in my 30s and living in Oakland, California, having moved there from the UK in 2015. I had always struggled with anxiety and panic attacks , but I was doing fairly well – until suddenly I wasn’t. I started having back-to-back panic attacks, wandering the streets of Oakland and nearby Berkeley in a desperate attempt to shake them, without success.

My life felt like an out-of-control fairground ride. Actually, it felt more like an entire theme park.…