This document discusses the role of psychologists in healthcare settings. It explains that psychologists are trained to understand how biological, behavioral, and social factors influence health and cognition. They can determine how behavioral or cognitive functions are altered, potential causes of alterations, and how to diagnose and treat mental dysfunctions. The document also notes that psychological testing is commonly used in medical settings, with the three fastest growing areas being quality-of-life assessments, neuropsychological assessments, and anxiety and stress assessments.