Treatment of panic disorder with agoraphobia: randomized placebo-controlled trial of four psychosocial treatments combined with imipramine or placebo

Few randomized controlled trials have included panic disorder patients with moderate to severe agoraphobia. Therefore, this population was studied using pharmacotherapy as well as psychotherapy. At the time of the study, imipramine was widely used as a pharmacological treatment. Also, current practice guidelines for patients with panic disorder find selective serotonin reuptake inhibitors and tricyclic antidepressants roughly comparable in terms of efficacy. Therefore, the main objective of this study is to compare four psychosocial treatments-cognitive and graded in vivo exposure treatments, graded in vivo exposure, cognitive treatment, and supportive therapy-to evaluate the benefits of combining cognitive therapy with exposure in vivo. These treatments were combined with imipramine or placebo for a total of eight experimental conditions. Participants presented moderate to severe agoraphobia. The method involved a randomized, double-blind, placebo-controlled trial with 137 participants who completed a 14-session protocol involving the treatments just mentioned. Measures were taken at baseline and posttreatment and at 3-, 6-, and 12-month follow-up. All treatment conditions were statistically and clinically effective in reducing self-reported panic-agoraphobia symptoms over the 1-year follow-up. No statistical differences were observed between imipramine and placebo conditions. This study found that all treatment modalities helped reduce panic and agoraphobic symptomatology over a 1-year follow-up period. These surprising results support the need to document the relations among the various components of an intervention. This would make it possible to assess the relative efficacy of the treatment components rather than of the intervention as a whole.