A Randomized, Double-Blind, Placebo-Controlled Study of the Effects of Adjunctive Paroxetine in Panic Disorder Patients Unsuccessfully Treated With Cognitive-Behavioral Therapy Alone

Background: Both cognitive-behavioral therapy and treatment with selective serotonin reuptake inhibitors (SSRIs) have proved to be effective in the treatment of panic disorder. The present study examined the effects of paroxetine added to continued cognitive-behavioral therapy in patients who were unsuccessfully treated with initial cognitive-behavioral therapy alone.

Method: 161 patients with panic disorder with or without agoraphobia (DSM-IV criteria) underwent a manual-guided cognitive-behavioral therapy of 15 sessions. Forty-three unsuccessfully treated patients from this group were included in a double-blind, placebo-controlled, next-step treatment study consisting of continued cognitive-behavioral therapy plus adjunctive paroxetine at a dose of 40 mg/day or continued cognitive-behavioral therapy plus placebo.

Results: Overall, patients in the cognitive-behavioral therapy plus paroxetine condition improved significantly on agoraphobic behavior (p<.05) and anxiety discomfort (p<.01), whereas patients in the cognitive-behavioral therapy plus placebo condition did not. Effect sizes in the cognitive-behavioral therapy plus paroxetine condition ranged from 1.0 to 1.8 and in the cognitive-behavioral therapy plus placebo condition, from 0.4 to 1.0.

Conclusion: Patients with panic disorder who are unsuccessfully treated with initial cognitive-behavioral therapy may benefit from the addition of an SSRI as a second treatment modality. The importance of timely evaluation of treatment results is emphasized.