 I want to flag up right at the start two things that shape the language I'm going to use through all of this book I'm reading from the introduction. Both were surprising to me. I was told by my doctor that I was suffering from both depression and acute anxiety. I had believed those were separate problems, and that is how they were discussed for the 13 years I received medical care for them. But I noticed something odd as I did my research. Everything that causes an increase in depression also causes an increase in anxiety, and the other way around.