Gauging the Effectiveness of Extended Imipramine Treatment for Panic Disorder with Agoraphobia

Background: Imipramine has proven efficacy for panic disorder. This study assesses the net effectiveness of systematic, open imipramine treatment in a homogenous sample of panic disorder patients with agoraphobia. Methods: One hundred and ten consecutive patients with DSM-III-R moderate to severe panic disorder with agoraphobia were treated with a fixed regimen of imipramine 2.25 mg/kg/day for 24 weeks. No instructions or encouragement for self-directed exposure to phobic situations or other coping strategies with panic or fear were given. Assessments were conducted at the end of the 2-week placebo run-in and at weeks 8, 16, and 24 of treatment. Results: Overall, 53% had a marked and stable response. Most measures revealed that substantial improvement continued beyond week 8 of treatment. Treatment success was accompanied with significant improvements in anxiety sensitivity, dysphoric mood, and functional well-being. Conclusions: These results provide a clinically relevant reference with which to compare the effectiveness of alternative treatments in providing nearly complete symptom remission in patients with primary panic disorder with agoraphobia.