LAUSR

BACKGROUND Impaired reflective functioning (RF) is common among patients with borderline personality disorder (BPD). Transference-focused psychotherapy (TFP) has been demonstrated to improve RF compared to other common BPD treatments. If RF reflects a treatment mechanism for TFP, differences in pretreatment RF may also serve as a prescriptive factor for TFP's effects. METHOD A total of 194 patients with BPD were randomized across two clinical trials to receive TFP (n = 83), dialectical behavior therapy (DBT; n = 31), supportive psychodynamic therapy (SPT; n = 28), or an enhanced treatment as usual (eTAU; n = 52). A mixed-effects model was used to examine whether baseline RF interacted with treatment condition to predict slopes of change in the Brief Symptom Inventory, the shared symptom outcome between trials. Moderation of changes in RF was also examined. RESULTS Treatment interacted with baseline RF to predict BSI slopes (p = .011). In TFP/SPT, RF did not predict outcomes, β = -0.00, p = .973, while higher RF was associated with relatively better outcomes in DBT/eTAU, β = -0.54, p < .001. Patients with poor RF (scores of 0/1) benefitted more from TFP/SPT, while patients with relatively ordinary RF (score of 4) had better outcomes in DBT/eTAU. Treatment effects on RF change were also moderated by baseline RF (p = .014), such that TFP improved RF most strongly among poor RF patients, SPT only among very poor RF patients, and DBT/eTAU not at all. DISCUSSION Low RF may reflect a deficit that may be targeted by TFP and other manualized psychodynamic treatments for BPD, which may be especially helpful among patients presenting with low RF. (PsycInfo Database Record (c) 2022 APA, all rights reserved).