Body dysmorphic disorder (BDD), also known as dysmorphophobia, is a severe and relatively common somatoform disorder (Phillips 2005a). DSM-IV-TR (American Psychiatric Association 2000) defines BDD as a preoccupation with an imagined defect in appearance; if a slight physical anomaly is present, the person's concern is markedly excessive. The preoccupation causes clinically significant distress or impairment in social, occupational, or other important areas of functioning, and it must not be better accounted for by another mental disorder (e.g., dissatisfaction with body shape and size in anorexia nervosa). According to DSM-IV-TR, patients with delusional BDD (i.e., those who are completely convinced that their view of their appearance is accurate and undistorted) may be diagnosed with both BDD and a psychotic disorder (delusional disorder, somatic type). This "double coding" implies that BDD's delusional and nondelusional variants may constitute the same disorder rather than being distinct subtypes, which is consistent with available data (Phillips 2004). Patients with BDD—both delusional and nondelusional patients—have high levels of distress, markedly poor functioning and quality of life, and high rates of suicidality (Cotterill and Cunliffe 1997; Phillips 2001; Phillips et al. 2005a, 2005b; Veale et al. 1996a). Thus, it is important to recognize BDD, accurately diagnose it, and provide effective treatment.