Emotional arousal is a key concept in most theories of change. In this empirical study the main interest was the relationship between Cognitive Therapy and Gestalt Therapy, the expression of emotion in the respective therapies and the improvement of depression. Since both treatments followed a group format, we were also interested if the emotional arousal expressed by the actively participating client was vicariously experienced by the observing group members. Results showed that vicariously experienced emotions were not likely. While the emotional experience of actively participating clients followed the respective treatment models, observing group members experienced other processes. Thus indicating that processes in groups may not follow the assumptions made in the respective treatment models. The relationship between emotional arousal and outcome was moderate and reflected differential outcome.