We've run quite a number of randomised controlled trials on self-help books. They work. https://www.ncbi.nlm.nih.gov/pubmed/22215865 https://www.ncbi.nlm.nih.g

We've run quite a number of randomised controlled trials on self-help books. They work. https://www.ncbi.nlm.nih.gov/pubmed/22215865 https://www.ncbi.nlm.nih.gov/pubmed/22215865