On the basis of several years of theoretical and empirical study of communication in a therapeutic group, this article deals with one particular problem: the specific type of text used in therapeutic communication - 'problem presentation in group therapy’ - is compared with the way patients present their problems in interviews. Linguistic criteria that can be used to evaluate the effectiveness of psychotherapy are illustrated in the process. At the same time, it is noted that - in harmony with the progress of the therapy - patients acquire a more realistic self-assessment of their own language behavior than persons tested who had no experience with therapy. The consequences for interdisciplinary research and also the practical results cannot be overlooked.