Short-term individual experiential schema therapy in adult outpatients with cluster C personality disorders: (How) does it work?

Rationale:

Cluster C Personality Disorders (PD) are the most frequently diagnosed PD, and are associated with severe impairments in daily life and comorbidity and high societal costs. Nevertheless, cluster C PD has received little attention for specific treatment options. Recent studies have shown preliminary evidence for the effectiveness of Schema Therapy (ST), but study results and literature are not conclusive about the necessary duration of ST to be effective. Meanwhile, the need for effective shorter treatment options is growing in both patients and society. Also, the effective components of ST are still largely unknown. Exploring the effects of specific ST techniques could make it possible to tailor treatment to an optimum. Experiential techniques provide a unique tool to address underlying needs and blocked emotions common in cluster C PD. Therefore, it is expected that a short-term ST treatment protocol that focuses solely on experiential techniques is effective in achieving (long-term) improvement in overall wellbeing, behavioral treatment goals attainment, negative core beliefs, general mental distress and PD severity.

Objective:

The aim of this study is to investigate the effect over time and working mechanisms of a short-term experiential ST protocol in adult outpatients with cluster C PD.
Study design: A non-concurrent randomized multiple baseline single case experimental design consisting of 4 phases (A1-B1-B2-A2), with a 6 months follow-up measurement moment. Primary outcome is assessed frequently, with a total of 53-64 measurements.

Study population:

12 patients with a DSM-5 principal diagnosis of cluster C PD, aged 18-65 years, recruited from a specialized mental healthcare facility in the Netherlands, GGZ Delfland.

Intervention:

Every participant receives the same intervention, starting with a randomised baseline waitlist period (A1), varying from 3 up to 6 weeks. This phase is followed by a pre-treatment phase (B1), consisting of five 45-60 minutes psycho-educative sessions aimed at increasing insight and motivation and developing a therapeutic relationship. Treatment phase (B2) consists of 18 protocolled 45-60 minutes experiential ST sessions. The treatment follow-up phase (A2) consists of 2 evaluative sessions, 1 month and 3 months after treatment.

Main study parameters/endpoints:

Primary outcome measure is overall wellbeing (ORS). Secondary outcomes are attainment of behavioral treatment goals (BTG), credibility of negative core beliefs (NCB), general symptomatic distress (BSI), cluster C PD severity (SCID-5-PD), early maladaptive schema (YSQ), and schema modes (SMI-1). The experience of participants with the experiential techniques in relation to increase in insight, satisfaction with the session and overall recovery will be explored (4 Q diary).

Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

Filling in questionnaires provides an extra time burden of 3.5 up till 5.5 hours and some participants will have to wait a bit longer than others as a result of randomization (although waiting time is still in line with normal procedures). Participants are assumed to receive state of the art treatment. It is expected that participants will benefit from the treatment. Results are accessible to participants and a final feedback session is offered wherein the final measurement outcomes are discussed, contributing to their insight in the change of their pathology. Participants receive a gift card of 10 euros for participating, the workbook is complimentary, and extra travel expenses will be fully compensated. No major disadvantages or adverse events have been documented before and are not expected.

The aim of this study is to investigate the effect of a short-term experiential Schema Therapy (ST) protocol in individual adult outpatients with cluster C Personality Disorders (PD) on overall wellbeing. Secondary outcomes are attainment of behavioral treatment goals, credibility of negative core beliefs, global symptomatic distress, cluster C PD severity, Early Maladaptive Schemas (EMS), and Schema Modes (SM). In addition, the experience of patients with experiential techniques in relation to increase in insight, change in core beliefs, satisfaction with the session and overall recovery will be explored.

A non-concurrent Single Case Experimental Design (SCED) will be used with a randomized baseline length phase (control phase), a pre-treatment phase (second attention-control phase), a treatment phase (ST), a treatment follow-up (FU) phase (2 ST follow-up sessions) and a 6 months measurement-FU (e.g. 6 months after active treatment phase, 3 months after treatment-FU phase).



It is hypothesized that:

1. Pre-treatment phase will not result in change in overall wellbeing, attainment of behavioral treatment goals, credibility of negative core beliefs, global mental distress, EMS and SM compared to baseline phase.

2. Adding experiential ST techniques after the pre-treatment phase is associated with an improvement in overall wellbeing and attainment of behavioral treatment goals and a decrease in credibility of negative core beliefs and global mental distress compared to baseline and pre-treatment phase.

3. At 3 months treatment-FU, EMS and dysfunctional SM will be decreased and healthy SM will be increased compared to baseline and pre-treatment phase.

4. Effects directly after treatment (hypothesis 2 and 3) will be maintained at 3 treatment treatment-FU and 6 months measurement-FU. At 6 months measurement-FU, PD severity will be decreased.

The timepoints are outlined in the description of the primary and secondary outcomes.

Baseline Phase

The baseline phase consists of a period of 3 up until 6 weeks waitlist period. No therapeutic interventions are offered during this phase, only measurements. Duration in baseline phase will differ among participants, depending on moment of allocation to a therapist after the final indication session. Randomization will be performed using the free scientific software Randomizer (https://www.randomizer.org/), creating a pre-determined randomization list.

Pre-treatment

In line with general guidelines and the used protocol in this study (e.g. short-term schema therapy, experiential techniques by Broersen and Van Vreeswijk, 2017), a pre-treatment phase is included. The aim of this phase is to increase insight, develop a therapeutic relationship and increase motivation to work on EMS and SM in the following phase. No active ST interventions aimed at changing pathology are conducted. Therefore, it is seen as a (second) ‘attention’ control phase (in line with the study of Renner and colleagues (2006)).

This phase comprises 5 sessions. Sessions are held on a weekly basis, with a duration of approximately 45-60 minutes per session. During the first session, the rationale of ST is discussed and patients are informed about their dominant EMS en modes. In the second and third session, a case-conceptualization and personal schema/mode model is made and psycho-education is provided about the common dysfunctional views in patients with cluster C PD on (children's) needs and emotions. The fourth session provides the opportunity to discuss the content of the former sessions more thoroughly and to make a crisis plan if needed. During the fifth session a schema/mode treatment contract is made, outlining the most important personal complaints, goals (BTG), EMS, SM and signs of change. In line with the protocol, this contract will be evaluated again in the first follow-up session.

If a session is cancelled due to illness or other circumstances, the session planned for that moment will be moved to the next session, extending the trajectory of treatment with 1 week. Only in case of a crisis situation, an extra individual crisis-intervention session will be held. If an extra session took place, this will be registered by the therapist.

Treatment phase

The treatment phase consists of 18 experiential ST sessions as written in the protocol ‘short-term schema therapy, experiential techniques’ of Broersen and Van Vreeswijk (2017).

In the first 10-15 minutes of a session homework and relevant experiences of the past week are addressed, in relationship to EMS/SM. After that, the technique as described in the protocol will be executed, related to the content of what has been discussed in the beginning of the session. At the end of the session, new homework is provided and explained. Session 1 through 15 are held on a weekly basis, with a duration of approximately 45-60 minutes per session. In line with the normal procedure to spread out sessions over several weeks when treatment progresses, session 16, 17 and 18 are held once every two weeks.

If a session is cancelled due to illness or other circumstances, the session planned for that moment will be moved to the next session, extending the trajectory of treatment with 1 week. Only in case of a crisis situation, an extra individual crisis-intervention session will be held. If an extra session took place, this will be registered by the therapist.

Treatment follow-up phase (A2)

Following protocol, the treatment-FU phase (A2) consists of 2 sessions with a duration of approximately 45-60 minutes per session, respectively 1 month and 3 months after the end of phase B2. These sessions are purely evaluative. No ST interventions are offered. At 3 months treatment-FU, results of the questionnaires will be discussed with the participant.

Every session outlined in the protocol has to take place in the same order for everyone and no sessions are skipped. In the event of a cancelled session, weekly measurements continue irrespective of session planning.