Group Schema Therapy for the Other Specified Personality Disorder: a pilot study.

Group Schema Therapy (GST) for Personality Disorders is getting increasingly popular in clinical practice. In particular the model developed by Farrell & Shaw (Farrell et al., 2015) has become popular for the more severe PD patients. Whilst there is some evidence for its effectiveness for Borderline PD (Farrell et al., 2009), a large group of patients currently receiving GST has an “Other Specified PD” (OSPD) as primary diagnosis (in DSM-IV labelled “PD Not Otherwise Specified”). This group consist of patients with PD traits, usually from different PDs, not meeting the threshold for a specific DSM-5 PD diagnosis, and is in many mental health care institutes a relatively large group. The evidence for the Farrell & Shaw GST model as a treatment for OSPDs is limited to a speculative generalization of findings in BPD and Cluster-C PDs (Farrell et al., 2009; Skewes et al., 2015). Apart from the problem that there is limited evidence for the effectiveness of GST for this specific group of patients, there is the problem that variations of GST are applied under the same label, which creates a barrier for quality maintenance and training of new therapist: what exactly is the protocol that should be used? It is therefore important that a well-defined protocol is tested in this specific patient population, with appropriate outcome measures, that assess the severity of manifestations of the pertinent PDs. As a first step an open trial is proposed to document effects of GST for OSPD. If successful, the next step will be a multicentre RCT comparing the protocol to a comparison condition, e.g. waitlist or Treatment as Usual (TAU).

The hypothesis is that patients who complete the 30-weeks group schema therapy will benefit from this treatment (i.e., a significant drop in severity in the manifestation of OSPD, as measured with ADP-IV, and secondary outcomes) at Post-Booster and Follow-up two years after starting the treatment program.

The outcome instruments will be assessed at Pretreatment (just before treatment starts, this moment will be counted as 0 months), at Mid-treatment (after 15 sessions of GST; this moment will be at 4 months approximately), at Post-treatment (after patients completed the 30 sessions GST; this will be at 8 months approximately), at Post-booster sessions (this will be around 12 months after start of therapy), and a Follow-up (two years after start of treatment).

Group Schema Therapy