Ever since psychotherapy has existed, there has been debate about whether and how it works. This is no different in the research history of the field of critical incident stress debriefing interventions. As early as the beginning of the 1960s, Caplan published fundamental considerations, and in 1979, Bordow & Porritt published a study in which they compared the “positive effects” of CISM interventions for traffic accident victims with those of a control group of thirty people.