Objective: Schema Therapy (ST) was developed for personality disorders, particularly borderline personality disorder. Although widely used in clinical practice, its evidence base remains limited and heterogeneous, with most research focusing on symptom reduction rather than psychosocial functioning. This systematic review and meta-analysis evaluated the effectiveness of ST in improving psychosocial functioning among individuals with personality disorders.

Method: Following PRISMA guidelines, a systematic search of PubMed, Embase, PsycINFO, and Cochrane databases was conducted up to 3 February 2026. Psychosocial functioning was the primary outcome, while quality of life, personality disorder severity, and early maladaptive schemas were secondary outcomes. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and random-effects meta-analyses were conducted where appropriate.

Results: Thirteen randomized controlled trials involving 1,664 participants were identified. Eight contributed to the quantitative synthesis. Meta-analysis found no evidence of a difference between ST and comparator conditions on psychosocial functioning (g = 0.20, 95% CI [-0.10, 0.49], I² = 57%). Similarly, no significant differences were observed for personality disorder symptom severity (g = 0.31, 95% CI [-0.57, 1.19], I² = 87%) or quality of life (g = 0.05, 95% CI [-0.22, 0.32], I² = 33%). Narrative synthesis yielded mixed findings.

Conclusion: Current evidence does not indicate that ST is more effective than comparator conditions in improving psychosocial functioning among individuals with personality disorders. However, the evidence base remains limited and heterogeneous. Further high-quality randomized controlled trials using standardized measures of psychosocial functioning are needed.