Preliminary Results on Acceptance, Feasibility, and Subjective Efficacy of the Add-On Group Intervention Metacognitive Training for Borderline Patients

Objective: The add-on intervention "metacognitive training for borderline patients (B-MCT)" targets cognitive biases in patients with borderline personality disorder (BPD). We aimed to evaluate acceptance, feasibility, and subjective use of this group intervention. Methods: Forty-eight inpatients with BPD were randomly assigned to 8 sessions of B-MCT versus an active control intervention (progressive muscle relaxation). Subjective use was assessed after 4 weeks. Results: B-MCT yielded significantly superior scores relative to the control group on several parameters, for example, use, fun, recommendation, and subjective improvements in symptomatology and cognitive abilities (e.g., perspective taking). Conclusions: The trial provides preliminary evidence for the acceptance and feasibility of metacognitive training in BPD. However, randomized controlled trials with larger samples and symptomatic outcomes are needed to investigate the specific impact of B-MCT on psychopathology and cognition.Keywords: borderline personality disorder; cognitive biases; metacognitive training; cognitionAlong with the cardinal symptom of affect dysregulation (Linehan, 1993), borderline personality disorder (BPD) may also manifest as impulsivity, problems with social interaction, and behavioral disorders (e.g., self-harm) as well as deficits in cognitive functioning, such as dissociative symptoms. Since the 1990s, a growing interest in cognitive processes in BPD has led to a more profound investigation of different facets of social cognition (e.g., theory of mind, interpersonal behavior, trust, and cooperation) and cognitive biases, that is, altered information processing as, for example, dichotomous thinking (for reviews, see Baer, Peters, EisenlohrMoul, Geiger, & Sauer, 2012; Dinsdale & Crespi, 2013). Distorted thinking styles seem to be related with difficulties in interpersonal functioning, frequently found among patients with BPD (Arntz & ten Haaf, 2012; Lazarus, Cheavens, Festa, & Zachary Rosenthal, 2014).Promising psychotherapeutic options have been developed (Barnicot et al., 2012; Stoffers et al., 2012), which target deficits in the ability to interpret behavior based on underlying mental states (mentalization-based therapy [MBT]; Bateman & Fonagy, 2004) or problems in interpersonal relations (e.g., dialectical behavior therapy [DBT]; Linehan, 1993). The available forms of psychotherapy provide symptom relief for a large proportion of the patients. However, they often do not lead to recovery (Zanarini et al., 2014). Many patients with partial BPD continue to suffer from significant psychological strain, poor quality of life, and impairments in psychosocial functioning (Zanarini, Frankenburg, Reich, & Fitzmaurice, 2010). In light of suboptimal therapy response of many patients and high costs of treatment (Soeteman, Hakkaart-van Roijen, Verheul, & Busschbach, 2008), it has become evident that there is a need for cost-effective and low-threshold measures to complement treatment options. Such an add-on concept was recently developed in form of the open-group metacognitive training for borderline patients (B-MCT; for a description of the training modules, see "Instruments" section and the Appendix). The training is derived from units of the metacognitive training for schizophrenia patients (MCT; for a review, see Moritz et al., 2014), which had been adjusted to address the specific dysfunctional thought patterns of patients with BPD. The B-MCT represents a complementary intervention for evidence-based standard treatments (especially DBT), which targets cognitive biases (e.g., Moritz et al., 2011; Schilling et al., 2012) in an entertaining manner. The intervention is thought to enhance metacognitive awareness (i.e., being aware of one's dysfunctional thinking styles). Patients are encouraged in rethinking premature conclusions and in considering alternative explanations (for a description of the training, see "Metacognitive Training for Borderline Patients" section, Appendix, and http://www. …