Combined pharmacological and behavioral treatment for agoraphobia.

Thirty-seven severely-disabled agoraphobics were randomly assigned to (1) Imipramine-no exposure. (2) Imipramine + exposure or (3) Placebo + exposure groups. To provide a more stringent test of the pharmacological effects of imipramine independent of exposure to phobic stimuli, Ss in the Imipramine-no exposure condition received antiexposure instructions during the first 8 weeks of therapy. Assessments were conducted at 0, 8 and 26 weeks. At 8 weeks, the group receiving imipramine combined with exposure therapy displayed more improvement than the other two groups, and was the only group to show a reduction in panic attacks. Ss receiving imipramine with antiexposure instructions showed little improvement on phobic indices, no reduction in panic, but significant improvement in anxiety and dysphoric mood. At 26 weeks Ss receiving the combined imipramine + exposure treatment exhibited further improvement resulting in a significant superiority of Imipramine + exposure over Placebo + exposure across a number of different outcome indices. Ss who had received imipramine with antiexposure instructions showed some improvement during the subsequent 18 weeks in which the antiexposure instructions were no longer in effect. However, neither this group nor the Placebo + exposure group showed a reduction in panic attacks. The results of the present trial provide support for the beneficial effects of combining intensive exposure with imipramine, but call into question the thesis that imipramine exerts its effect through a pharmacological blocking of panic attacks. Alternative hypotheses concerning the mode of action of imipramine are presented.