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

See 'METC onderzoeksprotocol chapter 1 (introduction, pages 8-10) for more
information.

Cluster C Personality Disorders (PD) are the most frequently diagnosed PD, and
are associated with severe impairments in daily life, high co-morbidity and
high societal costs (Bamelis, Evers, Spinhoven & Arntz, 2014; Drago, Marogna &
Søgaard, 2016; Eurelings-Bontekoe, Verheul & Snellen, 2012; Kenniscentrum
Persoonlijkheidsstoornissen, 2016; Olsson & Dahl, 2012; Skodol et al., 2005;
Weinbrecht, Schulze, Boettcher & Renneberg, 2016). Nevertheless, cluster C PD
has received little attention for specific treatment options (Arntz in van
Vreeswijk, Broersen & Nadort, 2012; Drago et al., 2016; Kenniscentrum
Persoonlijkheidsstoornissen, 2016; Renner et al., 2013). Fortunately, recent
studies have shown that, among others, Schema Therapy (ST) is a promising
psychotherapeutic intervention for mixed PD and cluster C PD*s. Duration of ST
treatment differed largely among these studies, with the total session amount
ranging between 20 and 65 sessions (Renner, et al, 2013; Renner et al., 2016;
Skewes, Samson, Simpson & van Vreeswijk, 2015; Van Vreeswijk et al., 2012;
Videler, et al., 2014; Videler, et al., 2017; Weertman & Arntz, 2007).
Meanwhile, the need for effective shorter treatment options is growing in both
patients and society ( (Olsson & Dahl, 2012; Skodol et al., 2005; (van
Vreeswijk & Broersen, 2017). Although the common tenet is that PD*s are
difficult to treat and requires long and intensive treatment (Skewes, Samson,
Simpson & van Vreeswijk, 2015), a few studies showed that even short-term
protocolled cognitive schema group therapy (20 sessions) achieved improvement
in overall symptoms, overall wellbeing, EMS, SM, depression and PD severity
(Renner et al, 2013; Skewes, Samson, Simpson & van Vreeswijk, 2015; Van
Vreeswijk et al., 2012; Videler et al., 2014). These results of short-term ST
are promising, but need to be extended.
Also, the effective components of ST are still largely unknown (Arntz, 2016;
Nordahl & Nysaeter, 2005). More insight in the effects of, and experiences
with, specific techniques on their own increases the possibility to tailor
treatment to a more optimum level (Arntz, 2016; Weinbrecht et al., 2016; Renner
et al., 2016).
Experiential techniques provide tools to reach and change underlying
(repressed) emotions and longings, which are generally seen as less sensitive
to cognitive techniques (Arntz, 2016; Artnz, 2012; Muste, 2016; Videler, 2016;
Young, 2003). Since patients with cluster C PD are inclined to put up a wall
and have the tendency to block underlying emotions and longings (e.g. avoidant
or controlling coping strategies) (Artnz, 2012; Muste, 2016), experiential
techniques are expected to be specifically potent at achieving (long-term)
improvement in pathology.
As a result, the aim of this non-concurrent Single Case Experimental Design
(SCED) study is to investigate the effect of a short-term experiential ST
protocol in individual adult outpatients with cluster C 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,
satisfaction of patients with the different experiential techniques and their
experience with the techniques in relation to increase in insight and recovery
will be explored.

Primary Objective:
To determine whether short-term experiential ST improves overall wellbeing in
adult out-patients with cluster C PD, directly after treatment, at 3 months
treatment follow-up (treatment-FU), and at 6 month measurement-FU.
6 months measurement-FU is defined as a measurement moment 6 months after
completion of the active treatment phase (B2) and thus 3 months after
completion of the treatment-FU (A2). This is due to the evaluative nature of
the treatment-FU sessions. No active interventions are performed during this
phase, thus it is not seen as active treatment.

Secondary Objectives:
- To investigate the impact of short-term experiential ST on attainment of
behavioral treatment goals, credibility of negative core beliefs, and global
symptomatic distress, directly after (pre)treatment, at 3 months treatment-FU
and at six months measurement-FU.
- To investigate the impact of short-term experiential ST on EMS and SM at 3
months treatment-FU and at 6 months measurement-FU.
- To determine the impact of short-term experiential ST on cluster C PD
severity at 6 months measurement-FU.
- To gain qualitative insight in the experience of patients with the different
experiential techniques. In specific, satisfaction with the different
experiential techniques and experience with the techniques in relation to
increase in insight and recovery will be explored.

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 (ORS) and two secondary outcomes (BTG and NCB) are
assessed frequently, with a total of 53-64 measurement points.

See the METC protocol 5.1 (page 16-17) for more information.

Pre-treatment (B1)
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 their 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.

Treatment phase (B2)
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). 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.

Treatment-FU phase (A2)
Following protocol, the treatment follow-up 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.

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

See the METC protocol 11.4 (page 30) for more information.

Extra time burden related to participating in the study is approximately 3.5 up
until maximum 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).
Also, filling in questionnaires and undergoing SCID-5-PD interview can be
confrontational. However, most of the used measurements are standard and
applied frequently in Dutch health care (exceptions being the BTG, NCB and 4 Q
diary). To the knowledge of the researcher, no serious adverse events have been
documented related to filling in the used questionnaires or to VAS-scoring (as
used for the BTG, NCB and 4 Q diary). Moreover, scoring BTG and monitoring
therapy progress could be considered a motivational factor in working on
goals/practicing new adaptive behavior (Turner-Stokes, 2018).
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.