- The optimal assessment of treatment outcome for studies assessing the efficacy of treatments for panic disorder has been a controversial topic. A recent National Institute of Mental Health (NIMH)-sponsored consensus conference addressed this important topic, and a summary paper regarding assessment of essential elements of the disorder resulted. Among other conclusions, it was agreed that several different domains should be considered as essential. This article reviews three pivotal studies assessing the efficacy of paroxetine for the treatment of panic disorder, and evaluates these studies for inclusion of those variables considered essential. Additionally, some data were reanalyzed to determine the percentage of individuals in these studies who are unequivocal responders (i.e., were both panic-free and rated on global assessment as responders). A longer-term treatment and relapse study is also mentioned briefly.