The added value of couple-based interventions compared to treatment as usual for patients with personality disorder.

Personality disordered individuals experience great difficulty dealing with
inner experiences, which causes problems with cognitions, emotions, behaviors
and interpersonal functioning. In personality disorders the emotional problems
(affectivity) play a central role; the variety, intensity, lability and coping
of emotional responses (DSM-5, APA 2013).
Learning to regulate emotions is in the development of an individual mainly a
dyadic process (Eurelings-Bontekoe et al., 2007). The focus on emotion
regulation problems is therefore focused on the transactions between the
individual and the environment and their interaction patterns (emerging in
childhood and perpetuating in adulthood). According to Linehan's biosocial
model (2016), emotion dysregulation is seen as a result of a biological
predisposition of the individual (emotional vulnerability), the (disabling)
environment and the interaction (transactions) between the two during a
individual's development. Emotion regulation is indeed an inner process, but
because of the interactive part of the regulation of emotions, the ability of
the significant other to regulate emotions is therefore also of immediate
importance. During development, this is the regulatory capacity of the parents,
in adulthood it can also be an signicifant other, such as a partner. The
partner brings his own ability to regulate emotions into the dyadic regulation.

Emotion regulation problems are most common in the intimate relationship(s) of
the individual. The partner relationship is therefore an important context in
which emotion regulation (problems) occurs and where treatment programs should
therefore be focused on (Whisman & Baucom, 2012). For most people the partner
relationship is the most important interpersonal relationship that is built up
during life, but that same partner relationship can be a source of stress and
negative dynamics. Some partners can be supportive and validating, but in other
cases they can also play an important role in perpetuating dysfunctional
patterns in the relationship (Snyder & Whisman, 2003) instead of offering an
adequate dyadic regulation of stress. Therefore, it is believed that treatment
programs for personality disorders can benefit from involving the partner in
treatment.

However, according to the (Dutch) Integrated Guideline Treatment for the
Treatment of Personality Disorders (Kenniscentrum persoonlijkheidsstoornissen,
2011) current effective psychotherapies are mostly focused on the individual
(the patient), with very limited attention for partners or other relatives.
This is striking, given that the close relatives have a lot to endure with the
patient, but can also provide support during treatment. The integrated
guideline treatment (2011) then describes that working together with family and
other relatives should be one of the general treatment principles for a solid
treatment program for personality disordered patients.
The importance of a system approach is also endorsed in the Multidisciplinary
Guideline for Personality Disorders (Landelijke stuurgroep Multidisciplinaire
Richtlijnontwikkeling in de GGZ, 2008) and should focus on restoring
relationships. According to the multidisciplinary guideline for personality
disorders, systemtherapy is suitable for all personality disorders, but
clinical practice shows that not many therapists involve the partner in
treatment. That seems like a missed opportunity. Family members, partners and
other relatives often react in their own way to their familymember with a
personality disorder, which can lead to relational problems. If the relative(s)
and the patient continue to function in the same way, dysfunctional patterns in
these relationships will be maintained, strengthened, and the desired change
will be held back. Moreover, when help is offered at an early stage, tension
and overload in relationships can be prevented. At the same time, family
members/partners can also be sources of healing and support and it would be a
loss to ignore or neglect their healing help.

Thus, from the integrated treatment guidelines for personality disorders, it is
believed that personality treatments could benefit from involving partners in
treatment. According to van Ee (2019), the goal of involving close relatives
(such as the partner) is to prevent interactions (patterns and dynamics) wich
unintentionally perpetuate or increase the psychological symptoms of the
patient. The aim is also that the partner (or relative) doesn't develop any
complaints or problems, but rather that the system's supporting capacity is
maintained or strengthened. In this way, patients and partners/relatives can
become aware of their mutual reactions to each other and understand how they
affect the other and vice versa.

Although the positive effect of system approach and couples therapy has been
demonstrated in various ways, Langeland (2019) concluded that little research
has yet been conducted into the efficacy of systemic interventions in the
treatment of personality disorders. It appears that during the treatment of
adults with personality disorders, systemtherapy is only added to the treatment
program upon the indication of the main practitioner. Laan and Rijken (2017)
from the Dutch Association for Relationship and Family Therapy (NVRG) also
recognize this phenomenon and believe that systemtherapy and couples therapy
should not replace individual (personality)treatment, but state that both
should exist side by side because both have their added value and can reinforce
each other.

In short, despite the fact that patients with personality disorders can
experience all kinds of difficulties in the partner relationship (and vice
versa), the involvement of the partner in personality treatment is
underrepresented in clinical practice and research into the effects of couples
therapy is lacking.
Current study examines the added value of couple-based interventions in the
treatment of patients with a personality disorder, whereby the outcome measures
are **dyadic coping (the cooperation and communication of the couple; learning
to handle stress together) and the overall functioning of the patient and
partner.

The purpose of this study is to contribute to the knowledge of couple-based
interventions for patients with personality disorder.
Personality disordered patients often experience great difficulty in adequately
regulating their emotions and behaviors and have recurring problems in
relationships, work and social functioning.
For many people, the partner relationship is one of the most important intimate
interpersonal relationship built in life. However, the presence of a
personality disorder can have a major (negative) influence on the quality of
the partner relationship and partners can play an important role in maintaining
dysfunctional interaction patterns. From the treatment guidelines for
personality disorders it is believed that personality treatments could benefit
from involving the partner in treatment. However, according to recent research
from Langeland (2019 little is known about the effectiveness of couples therapy
and couple-based interventions in the treatment of patients with personality
disorders.

Design:
Current study uses a (non-concurrent) multiple baseline design, enabling to
assess the participants at different times. This within-subject design does not
involve an independent control condition/group, but the participants are used
as their own controls. Repeated measures are taken within the same participants
to determine the effect of the experimental condition (the couple-based
interventions). A non-concurrent multiple baseline design is essentially a
series of A-B replications in which the length of each baseline phase is
different (Morley, 2017).
[Figure 1 in the researchprotocol shows a visual schematic representation of
the multiple baseline design in current research].

This multiple baseline design uses an A-B-A construction;
Phase A (baseline) is the treatment as usual (TAU), an evidence-based group
psychotherapy for personality disordered individuals (dialectical behavioral
therapy (DGT), psychodynamic therapy (PD) or schema focused therapy (SFT)).
The participants are randomly assigned to a baseline condition (see chapter
5.2. of the researchprotocol) in which the participant follows 2, 4 or 6
sessions of the treatment as usual (phase A).
Then in phase B there is an addition of 8 sessions op couples therapy (EXP) at
the continuing TAU.
Finally, after phase B, phase A follows again for 6, 4 or 2 sessions TAU. This
serves as a follow-up period and ensures that all patients have had the same
amount of sessions in total (counterbalancing).

In total 17 measurements will take place (patient and partner). A baseline
measuring moment (T0) is performed before therapy starts and after that weekly
measurements will take place over an 16-week study period.

Regular treatment:
All patients follow a treatment as usual which consists of an evidence-based
group treatment for personality problems, which are given by experienced and
trained therapists. The group treatments take place weekly and last 1.5 to 2
hours.
During the total study period (phase A + B + A), the patients follow a total of
16 sessions of group treatment and (in phase B) 8 additional sessions of
couples therapy. These sessions with patient and partner take place weekly and
last 60 minutes.

Intervention:
For the couples therapy sessions, a pluralistic model by Snyder and Whisman
from 2003 is used (Snyder & Balderrama-During, 2012).
[The format is shown in appendix 1 of the research protocol.]
This format offers a pluralistic model based on the principle that the
different couples in therapy will vary in the interventions that are needed at
different stages of treatment. These interventions are based on the couple and
in which phase of the model they are ("couple based interventions") and provide
insight into how the patterns of the couples contribute to stress and
dysfunction in the relationship.
The used format was used in previous scientific research at the Department for
Personality Disorders (PsyQ CPP, The Hague, the Netherlands) by de Vos,
Marissen and Slotema in 2016 (see METC protocol ID: NL55559.058.16).

The couples therapy sessions are carried out by systemtherapists at PsyQ CPP
and the PsyQ Systemtherapy department, who all have experience and affinity
with patients with personality problems and couples therapy. In order to strive
for uniformity (treatment integrity) in the use of the format, monthly
supervision meetings will be organized.

No risks or undesirable effects are expected in current study because the
participants first start with their regular evidence-based group treatment for
personality disorders (treatment as usual). The couples therapy sessions are
added in treatment phase B as an additional treatment offer/intervention to
achieve a quality improvement in the partner relationship. The couples therapy
sessions are aimed to improve the communication, cooperation and the coping of
the couple.
It is not in line with general expectations that couples therapy entail risks
or negative effects (side effects). In fact, the expectations regarding current
study are that offering couples therapy sessions at the beginning of a
personality treatment program will have positive effects in the terms of
involvement, resilience and dyadic coping of the couple, as well as positive
effects on the overall functioning of the patient.
If the patient and/or partner experience severe stress or crisis, their main
practitioner from PsyQ (psychiatrist or clinical psychologist) can be contacted
for support (during office hours), to assess what is needed at that time.
Outside office hours and weekends, contact can be made with their general
practitioner.