In the conclusion of this two-part article, the authors present the notion of psychiatric confounders to assist non–psychiatric physicians in assessing the “difficult pain patient.” Non–psychiatric physicians need not have a detailed understanding of all psychiatric diagnoses, but an understanding of certain diagnoses will assist in evaluating patients with enduring pain complaints. Psychosocial factors have important effects on the relationship between pain and disability. In one study, job satisfaction was a predictor of future disability in low back pain patients; in another study, psychiatric morbidity in a pain-free population predicted the development of back pain over a defined period. In many patients with persistent somatic and/or pain complaints, unrecognized psychiatric diagnoses drive or complicate symptoms and may precede the onset of low back pain. Mood, anxiety, and substance abuse disorders are common and can be associated with physical and pain complaints. Somatic symptoms often are the core feature of the depressed patient who presents to a primary care physician. Somatoform disorders are a spectrum of psychiatric disorders in which physical complaints are driven or aggravated by psychological factors; somatizing patients have chronic problems, many of which are pain-related and involve recurrent physical symptoms, often in different bodily systems, that wax and wane over time. Physicians who evaluate patients with pain complaints must understand the complexity of the challenge, including the probability that pain complaints indicate underlying psychopathology.