To the Editor: I found the American Psychiatric Association’s "Practice Guideline for the Treatment of Patients With Panic Disorder"(1) surprisingly disappointing in two regards. 1) There was no mention of the speculative etiology of panic disorder. Is it psychologically rooted, and if so, how does it differ psychodynamically from anxiety disorder? Or is it, as I believe, organically determined? 2) I have been using clonazepam extensively in the treatment of patients with panic disorder for the past 15 years, with 100% efficacy (this includes patients previously resistant to monoamine oxidase inhibitors and tricyclic antidepressants, as well as long-term sufferers) and absolutely no tendency toward addiction (despite using it with a large homeless population that included a high percentage of drug addicts).