<h3>Context</h3> Dialectical behavior therapy (DBT) is a treatment for suicidal behavior and borderline personality disorder with well-documented efficacy. <h3>Objective</h3> To evaluate the hypothesis that unique aspects of DBT are more efficacious compared with treatment offered by non–behavioral psychotherapy experts. <h3>Design</h3> One-year randomized controlled trial, plus 1 year of posttreatment follow-up. <h3>Setting</h3> University outpatient clinic and community practice. <h3>Participants</h3> One hundred one clinically referred women with recent suicidal and self-injurious behaviors meeting<i>DSM-IV</i>criteria, matched to condition on age, suicide attempt history, negative prognostic indication, and number of lifetime intentional self-injuries and psychiatric hospitalizations. <h3>Intervention</h3> One year of DBT or 1 year of community treatment by experts (developed to maximize internal validity by controlling for therapist sex, availability, expertise, allegiance, training and experience, consultation availability, and institutional prestige). <h3>Main Outcome Measures</h3> Trimester assessments of suicidal behaviors, emergency services use, and general psychological functioning. Measures were selected based on previous outcome studies of DBT. Outcome variables were evaluated by blinded assessors. <h3>Results</h3> Dialectical behavior therapy was associated with better outcomes in the intent-to-treat analysis than community treatment by experts in most target areas during the 2-year treatment and follow-up period. Subjects receiving DBT were half as likely to make a suicide attempt (hazard ratio, 2.66;<i>P</i> = .005), required less hospitalization for suicide ideation (F<sub>1,92</sub>=7.3;<i>P</i> = .004), and had lower medical risk (F<sub>1,50</sub>=3.2;<i>P</i> = .04) across all suicide attempts and self-injurious acts combined. Subjects receiving DBT were less likely to drop out of treatment (hazard ratio, 3.2;<i>P</i>&lt;.001) and had fewer psychiatric hospitalizations (F<sub>1,92</sub>=6.0;<i>P</i> = .007) and psychiatric emergency department visits (F<sub>1,92</sub>=2.9;<i>P</i> = .04). <h3>Conclusions</h3> Our findings replicate those of previous studies of DBT and suggest that the effectiveness of DBT cannot reasonably be attributed to general factors associated with expert psychotherapy. Dialectical behavior therapy appears to be uniquely effective in reducing suicide attempts.

Two-Year Randomized Controlled Trial and Follow-up of Dialectical Behavior Therapy vs Therapy by Experts for Suicidal Behaviors and Borderline Personality Disorder