In total, 25 chapters address a series of diagnostic categories. Each of these chapters rigorously focuses on what is currently available in the medical literature. Specific attention is given to the type of studies analyzed. That is, randomized, prospective clinical trails with blinded assessments; clinical trails with interventions but without double-blind methodological techniques; open treatment studies aiming at securing pilot data; reviews with secondary data analysis; reviews without secondary data analysis; and, finally, reports based on case studies, essays, and opinions. In other words, the editors and contributors make a strong effort to differentiate the scientific nature and validity of what the medical literature has offered so far.