In stage 1 of the treatment, therapy is focused on getting behavioral control. Some people who enter treatment at this stage are actively struggling with life threatening behaviors (e.g. cutting, suicide attempts, excessive drinking), treatment interfering behaviors (e.g. dropping out of treatment, skipping therapy) and major quality of life interfering behaviors (e.g. risk of losing housing, being expelled from school, losing an important relationship).
The rationale for focusing on gaining behavioral control at this point is that it is assumed that a life lived out-of-control is excruciating. Progress cannot be made on underlying emotional issues until you have the skills to manage emotion without engaging in maladaptive behaviors and are committed to the process of therapy.