Patients with panic disorder are frequently medicated when they participate in psychotherapy such as cognitive behavioral therapy (CBT). The present study examined the effects of overall medication status, medication type (benzodiazepine versus antidepressant), and medication dose in a large sample of patients with panic disorder (N=178) participating in CBT. Overall, medications exhibited very little effect on outcome. After controlling for the effects of CBT, however, taking higher doses of antidepressants was associated with poorer end-state functioning. Results are discussed in relation to better understanding the role of combining psychopharmacological and psychosocial treatments for panic disorder. Keywords: panic disorder; medication; cognitive behavioral therapy, treatment Epidemological evidence suggests that panic disorder (PD) afflicts millions (Kessler et al., 1994). Individuals with PD experience marked impairment (Simon et al., 2002) and are at an increased risk for alcohol use disorders (Otto, Pollack, Sachs, O'Neil, & Rosenbaum, 1992), smoking (see Zvolensky, Schmidt, & Stewart, 2003, for review), and suicide attempts (Schmidt, Woolaway-Bickel, & Bates, 2001). Fortunately, efficacious treatments for PD are available including several types of pharmacotherapies as well as cognitive behavioral therapy (CBT) (Schmidt, Koselka, & Woolaway-Bickel, 2001). Antidepressants such as monoamine oxidase inhibitors (MAOIs), tricydic antidepressants (TCAs), and serotonin selective reuptake inhibitors (SSRIs) are among the psychotropics that have demonstrated the highest levels of efficacy in the treatment of PD (see Schmidt, 1999, for review). Antidepressants have become the medication of choice in the pharmacological treatment of PD, reducing panic-related symptoms without causing the withdrawal and dependency that can occur with benzodiazepines. Yet, benzodiazepines are appealing hi that they provide more rapid anxiolytic effects and therefore continue to also serve as a common treatment for PD. In terms of psychotherapy, research has consistently demonstrated that CBT is one of the most efficacious treatments for PD (see Barlow, Raffa, & Cohen, 2002, for a review). CBT for PD is a highly structured, skill-based treatment in which the therapist works with patients to modify thinking and behaviors that maintain PD. Techniques utilized in CBT include education, cognitive reappraisal, interoceptive exposure (i.e., repeated exposure to bodily sensations associated with the fear response), in vivo exposure (i.e., repeated exposure to external situations connected to the fear response), and breathing control techniques. The efficacy of both psychopharmacology and psychosocial treatments for mental disorders has led some to assume that combined treatments, in which psychotherapy is coupled with pharmacotherapy, may be superior to singular ones. In fact, over half of patients receiving mental health services have been found to receive a combination of psychotherapy and medication (Pincus et al., 1999). In the case of PD, the majority of patients presenting for psychosocial treatments are medicated. It is therefore critical to determine the effects of medication use on psychosocial treatment for PD. Overall, there is little work on the combined effects of medication and CBT for PD. Among the antidepressants, there is some support for the short-term superiority of the combination of CBT plus fluvoxamine (de Beurs, van Balkom, Lange, Koele, & van Dyck, 1995) and CBT plus paroxetine (Stein, Norton, Walker, Chartier, & Graham, 2000) relative to CBT alone or CBT plus placebo. However, evidence suggests that the preliminary benefits of combining antidepressants with psychosocial treatments are often lost during follow-up and that combined treatment may actually result in poorer long-term outcome. In the case of CBT plus imipramine, Barlow, German, Shear, and Woods (2000) found that the combined treatment resulted in better initial outcome, but CBT alone predicted the best outcome at 6-month follow-up. …