I think that's a huge question. Dr. S lists a variety of reasons for low cortisol, most of which are severe or rare. More of the emphasis seems to be on high cortisol levels. I haven't read every single page of the book yet, but I don't think that she gives specifics about test results (i.e. what they mean). It could be that you have burnt out adrenal glands. But why would your doctor recommend you go to a psychiatrist for that problem? That sounds a little bizarre.