Most other disorders do not have formally defined treatment-resistant subtypes, but the prevalence of persistent and debilitating symptoms is a ubiquitous problem. For example, in patients with anorexia nervosa, the authors emphasize that almost every patient has very difficult-to-treat symptoms, that full remission is rarely achieved, and that most patients have at least some “treatment resistance.” Similarly, in the chapter on personality disorders, Dr. Gabbard emphasizes that personality disorders have always been difficult to treat and that the term “treatment resistant” could also be designated “more difficult than usual.” This chapter offers a surprisingly hopeful assessment of the long-term outcome for patients with treatment-resistant personality disorders. For example, a recent 10-year prospective study of patients with borderline personality disorder, funded by the National Institute of Mental Health, found that over 90% of patients achieved remission of symptoms that lasted at least 2 years, although somewhat over 30% of remitted patients subsequently experienced a relapse. Furthermore, at least seven distinct psychotherapeutic approaches for borderline personality disorder have demonstrated efficacy in randomized controlled trials. This therapeutic armamentarium should help practitioners individualize treatment approaches for their patients.