The issue of difficult classes is becoming increasingly relevant, as everyday practice in schools confronts teachers and psychologists not only with individual cases of adolescents who are difficult to control and influence socially, but also with entire classes exhibiting group behavior that falls outside established norms. The introduction of the term "difficult class" makes it possible to study problematic phenomena not only in their individual form, but also in their group, collective form. Moreover, with the transition from individual to collective form, some new characteristics, traits, and manifestations of individuals belonging to the group and acting as a whole community appear in the phenomenon. The monograph is intended for a wide range of specialists and researchers in the fields of psychology and pedagogy, as well as for institutions, experts, teachers, and students, and any reader interested in the origins, structure, multiple manifestations of this type of class, as well as the scientifically based approaches for its sustainable corrective impact.