Manualized psychological therapies yield small significant improvements in BPD symptom severity for adolescentsManualized Psychological Therapies Show Small Gains for Adolescent BPD

ObjectiveThis meta-analysis evaluated the efficacy of psychological interventions for adolescents with borderline personality disorder (BPD) across multiple outcome domains, including BPD symptom severity, emotion regulation, depressive symptoms, general psychopathology, and quality of life.MethodsFollowing PRISMA 2020 guidelines (PROSPERO: CRD420261306339), we searched PubMed, PsycINFO, Embase, and Cochrane CENTRAL from inception through January 2026. RCTs of manualized psychological therapies for adolescents aged 12–18 years with BPD or significant BPD features were included. Two reviewers independently extracted data and assessed risk of bias using the Cochrane RoB 2.0 tool. Random-effects meta-analyses were conducted using Hedges’ g, with I² for heterogeneity and Egger’s test for publication bias.ResultsTwelve RCTs comprising 844 adolescents (mean age = 15.8 years; 81% female) were included. Interventions included DBT-A, MBT-A, CAT, ERT, UP-A, and school-based programs. Psychological interventions produced small significant effects on BPD symptom severity (k = 8; n = 636; SMD=−0.27; 95% CI [−0.47, −0.06]; p = 0.012; I²=25%), emotion regulation difficulties (k = 5; n = 304; SMD=−0.26; 95% CI [−0.48, −0.04]; p = 0.020; I²=0%), and general psychopathology (k = 6; n = 302; SMD=−0.34; 95% CI [−0.56, −0.12]; p = 0.003; I²=0%). No significant effects were observed for depressive symptoms (k = 7; n = 479; SMD=−0.13; 95% CI [−0.35, 0.09]; p = 0.240) or quality of life (k = 2; n = 126; SMD = 0.05; 95% CI [−0.33, 0.43]; p = 0.800). Heterogeneity was low across all outcomes (I²=0–29%), and Egger’s test indicated no significant publication bias (all p>0.15). Exploratory subgroup analyses by intervention type were limited by single-study subgroups and could not reliably establish differential efficacy. Available follow-up data suggested progressive erosion of treatment gains over 12–36 months.ConclusionPsychological interventions for adolescent BPD produced statistically reliable but small improvements in BPD symptoms and emotion regulation, with effect magnitudes that likely fall below clinically meaningful thresholds. No benefits were detected for depressive symptoms or quality of life. Current treatments should be viewed as beneficial but limited. Future research should prioritize adequately powered head-to-head trials, longer follow-up with maintenance interventions, and development of treatments with broader impact across outcome domains.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD420261306339.