Day hospital Mentalization-Based treatment versus Intensive Outpatient Mentalization-Based Treatment for patients with severe borderline personality disorder: A multi-centre head-to-head randomized clinical trial

Borderline personality disorder (BPD) generates a high burden to individual
patients, society, health care, and economy, and this is especially true for
patients with severe BPD. Until recently, these patients were often refused
(curative) treatment, as clinicians were pessimistic about their change
potential, and mental health care lacked specialized programs for this group.
These patients typically display multiple problem behaviors that interfere with
their own and others* treatments (e.g., violence, aggression, substance misuse,
acting-out, non-adherence). Implementation of treatments for this group is thus
important for not only the patients themselves, but also in order to reduce the
burden on mental health care, and the inefficient use of resources. Studying
the cost-effectiveness of various treatment options will also likely increase
health benefits in the short term and a reduction in health care consumption
and costs in the long run.

The Mentalization-Based Treatment (MBT) model assumes that enhancing the
capacity for mentalization (i.e., the capacity to interpret the self and others
in terms of internal mental states) improves functioning of severe BPD
patients. Two RCTs demonstrated the effectiveness of Mentalization-Based
Treatment for patients with severe BPD in a Day Hospital setting (MBT-DH) as
compared to usual care, and for MBT in an intensive outpatient setting
(MBT-IOP) as compared to structured clinical management. Yet, in these trials,
patients in MBT-DH and MBT-IOP differed substantially in terms of symptom
severity at baseline, which makes it impossible to model an 'indirect
comparison'. Moreover, substantial cost differences between both MBT-variants
exist: MBT-DH consists out of 5 day a week treatment, while MBT-IOP is about
1.5 days. Such cost-differences warrant a *head to head* cost-effectiveness
study. The aim of this trial is therefore to study the
(cost-)effectiveness of MBT-DH as compared to MBT-IOP.

The primary aim of this study is to investigate the efficacy of MBT-DH in
comparison to MBT-IOP. A secondary aim is to explore the cost-effectiveness and
matching potential of various baseline variables that might help treatment
selection procedures and optimizing (cost-)effectiveness.

In order to assess the (cost-)effectiveness of MBT-DH and MBT-IOP, a randomized
controlled trial will be performed in a clinical setting. Three mental health
care institutes with four treatment locations are involved in this study: 1)
The Viersprong, location Bergen op Zoom, 2) The Viersprong, location Amsterdam,
3) Arkin, location Amsterdam, and 4) Lentis, location Groningen. Two locations
(1 and 3) will each realize two MBT-DH groups and two MBT-IOP groups
exclusively consisting of randomized patients participating in the trial. The
other two locations (2 and 4) will each conduct one MBT-DH group and one
MBT-IOP group, with all treatment groups consisting of randomized patients
participating in the trial.

All consecutive patients referred to the MBT-ward of these treatment centers
are contacted by a psychotherapist. During a first individual meeting with this
psychotherapist, patients are further screened for exclusion criteria, and
receive information about the trial and treatments.
They have a week to consider their participation in the trial. After the
individual meeting, the MBT-indication of every patient is discussed by the
MBT-team. There are two options: 1). The MBT-indication is made definite 2).
MBT-indication is not supported by the MBT-team and patient is sent back to the
intake team. After this meeting, the patient is invited for a face-to-face
meeting with the psychotherapist. The psychotherapist explains to the patient
the decision of the MBT-team concerning MBT-indication and asks if the patient
agrees with this. If the MBT-indication is made definite, and the patient is
willing to participate in the trial, informed consent is signed. Then, the
patient fills in the first set of questionnaires and afterwards the patients
will be randomized to one of two groups: MBT-DH or MBT-IOP.

Both MBT-dosages have a treatment duration of max 18 months, followed by a
maintenance phase (also 18 months max). Patients are assessed at day of
definite indication for MBT, at the start of treatment and 6, 12, 18, 24, 30
and 36 months after the start of treatment. If patients refuse to participate
in the study, they will be offered standard care in the same treatment centre.

MBT-DH is provided 5 days/week and includes daily group psychotherapy, weekly
individual psychotherapy, and art- and writing therapy. MBT-IOP includes group
psychotherapy twice a week and weekly individual psychotherapy. Both
MBT-dosages have a treatment duration of max 18 months, followed by mentalizing
maintenance sessions (also 18 months max).

Participation involves minimal risk. MBT will be delivered by experienced
professionals used to working with patients with BPD features. Participation in
the trial involves a number of relatively time*consuming interviews and
assessments which may be somewhat burdensome but do not carry specific risk.
Studies have not shown iatrogenic effects of MBT. By contrast, studies have
shown that MBT is associated with symptom and interpersonal improvement,
decreases in self-harm, crisis interventions, and parasuicidality. Moreover,
the safety board (see XX), will monitor any potential adverse events (e.g.,
suicide) that might be associated with the treatment, which may ultimately lead
to stopping the trial or a treatment arm should this be warranted by the nature
and/or frequency of the adverse events.