Results for stand-alone designs showed similar outcomes with favorable efficacy for investigated psychotherapies than control interventions including self-harm (g=0.32; 95% CI, 0.09–0.54), suicide (g=0.44; 95% CI, 0.15–0.74), health service use (g=0.40; 95% CI, 0.22–0.58), and general psychopathology (g=0.32; 95% CI, 0.09–0.55). However, dialectical behavior therapy (g=0.34; 95% CI, 0.15–0.53) and psychodynamic approaches (g=0.41; 95% CI, 0.12–0.69) were the only two types of psychotherapies more effective than control interventions.
By assessing the trials through 4 domains of Colchrane Collaboration Risk of Bias tool, the researchers found that the risk of bias was a strong moderator in both subgroup and meta-regression analyses. The authors stated that this bias inflated their findings. Future studies, they say, are needed to clarify the stability and practical relevance of dialectical behavior therapy and psychodynamic treatment in BPD specific psychotherapies.