If I recall correctly, Dr. Sarno wrote in one of his TMS books about the patient who told him she could not make the "leap of faith" he prescribed. He told her she did not need to make a leap of faith but rather a leap of understanding. That might have been word play, but I think it is easier to keep the belief needed to recover from TMS and its equivalents, like dizziness and headaches, if one has a scientifically based understanding of what is going on in his or her body to produce the symptoms.
With resect to science-based understanding of symptoms lacking an identifiable structural cause, I need to preface what I am going to say with the caveat that I am a rank amateur when it comes to physiology. But here goes:
Sarno's chief psychologist and coworker for over thirty years, Dr. Alene Feinblatt, was trained in and practiced a form of therapy called ISTDP (Intensive Short-Term Psychotherapy). The cornerstone of ISTDP is that somatic symptoms lacking conventional medical explanation are due to unconscious anxiety, meaning physiological changes triggered by unconscious anger, guilt about the anger, and grief. Because we learned early in life that these emotions are dangerous or painful, we innately seek to distract ourselves from experiencing them with defense mechanisms (thinking or doing things that occupy our minds so there is no room for the emotions). At one level, the sympathetic nervous system produces the physiological changes of unconscious anxiety. These physiological changes affect mainly the striated muscles and can cause symptoms such as back pain, neck pain, chest pain, tension headache and so on. At a higher level of unconscious anxiety, the parasympathetic nervous system dominates. It affects mainly the smooth muscles and can cause symptoms such as acid reflux, irritable bowel syndrome, other stomach and bowel symptoms, bladder dysfunction, and so on. At a still higher level of physiological changes, the symptoms can include migraine, dizziness, tinnitus, visual blurring, fainting, and so on. For example, a leading ISTDP therapist has written that fainting due to "parasympathetic discharge of anxiety occurs after symptoms of nausea, jelly legs, and lightheadedness. . . . blood vessels dilate, reducing blood pressure in the brain, leading to cerebral hypofusion," i.e., decreased blood flow.
Dr. Allan Abbass, a psychiatrist specializing in ISTDP, and Dr. Howard Schubiner, who is well known to readers of this website, have a forthcoming book titled Hidden From View: A Clinician's Guide to Psychophysiologic Disorders. They wrote it to educate family medicine doctors and other healthcare professionals about this sort of stuff so that more patients will get better informed treatment for psychophysiologic disorders than is the case now. Let us hope it will have a big impact.