Brief group-based psychological treatments are a common tool for increasing service access. Dialectical behavior therapy (DBT) skills groups have been used with several clinical populations to improve emotional regulation. This research aimed to examine the effectiveness of DBT-informed classes across four treatment settings in reducing symptoms of depression, anxiety, and emotional dysregulation, as well as examining participant factors associated with treatment responsiveness and class dropout. A total of 315 participants completed pre-post measures as a part of standard clinical care. Linear mixed model analyses showed that participants who completed DBT-informed classes experienced significant reductions in symptoms of depression, anxiety, and emotional dysregulation. Only an individual's baseline DSM-5 score significantly predicted responsiveness to treatment in terms of decreasing symptoms of anxiety, depression, and emotional dysregulation.