Norman Cousins Lecture https://www.sciencedirect.com/science/article/pii/S0889159105001856 https://sci-hub.tw/10.1016/j.bbi.2005.09.008 https://www.urmc.rochester.edu/people/20019181-nicholas-cohen
And there is still so much to learn about the nervous, endocrine and immune systems of the human body. Making discoveries here will provide us with better understanding of the interplay of mind and body. Psychology IMO is so far mostly sandcastles on the beach. It needs the data and structure of hard science.
IMO this is just a dressed up way to blame people for their illnesses. People have of course been told, "You're not trying hard enough to overcome your terminal cancer. If you really wanted to recover, you would." But because this is "validated" as science, the average person's protestations are dismissed.
I once have read the 1975 article by Ader and Cohen. In a later article from the 90´s, I believe, they sounded dangerously optimistic, but back in 1975 they explicitly said that their conclusions have been drawn from healthy animals, obviously indicating that one must not mix things up. Sadly ppl tend to forget to be honest and humble.