One of the difficulties that clinicians face is that a typical clinic patient often does not resemble the sanitized patients selected for in research studies. Most published reports evaluating the efficacy of psychoactive drugs in psychiatric patients carefully select physically healthy adult, but not geriatric, pediatric, or pregnant, patients. Unfortunately, in clinical practice, physicians frequently encounter patients with psychiatric disorders who are also pregnant, juvenile, elderly, brain damaged, or medically ill but who are otherwise appropriate candidates for conventional pharmacotherapy. Since the last edition of this book, much has been learned about treating special populations with psychotropic agents. In this chapter, we address some of these special situations.