The (cost-)effectiveness of generalist (GIT-PD) versus specialist treatment (MBT/ST) for severe personality disorders (the P-DAET study): a pragmatic randomized controlled non-inferiority trial

There are long waiting lists for the treatment of personality disorders. This
is partly due to the fact that there are too few specialized psychotherapies
available and that the training courses for these psychotherapies are quite
long and expensive. That is why the GIT-PD, Guideline-Informed Treatment for
Personality Disorders (GIT-PD), was developed. GIT-PD is a generalized approach
that is based upon functional components from other forms of treatment. GIT-PD
can be easily applied by many practitioners. There is clear evidence that this
works as well as specialized psychotherapies for many patients, but this has
not yet been properly investigated in a direct comparison. Nevertheless, GIT-PD
is already being used in many institutions.

To compare the effectiveness of a generalist approach (GIT-PD) to specialized
psychotherapy for personality disorders (PD) and to predict for which
individual patient generalist treatment is not inferior to specialist
treatment.

This is a pragmatic randomized controlled non-inferiority trial in which
people with severe personality pathology receive either general treatment or a
highly specialized form of psychotherapy (Schema Focused Therapy or
Mentalization Based Treatment).
The main outcome measure is level of personality functioning after 1.5 years of
therapy. In addition, an effect is expected on the severity of the symptoms,
quality of life and social and professional functioning. This is determined
after 3, 6, 12, 18, 24 months of treatment and one year after the end of
treatment.

Participants will be recruited from the following mental health institutes:
Altrecht, Arkin, Dimence, GGZ Oost-Brabant, and de Viersprong. Patients meeting
the inclusion criteria will be informed about the study by the clinician at
intake phase. They will be handed out a brochure with information about the
study and an informed consent form. Then, they will be given a week to consider
participation in the study. After signing informed consent, a baseline measure
will take place (see Flowchart and Table 1). The baseline measure will be
conducted by research assistants and will take about 1.5 hours to complete.
Then, randomization takes place by an independent statistician. The research
assistant receives the information on the allocation from the independent
statistician and informs the patient about which treatment has been assigned.
Participants will undergo either GIT-PD treatment or SFT/MBT treatment. During
treatment, there will be five follow-up measurements (see Flowchart). The
follow-up measures at 3, 6,12, and 24 months will take about half an hour,
while the measures at 18 months and at one year after completing treatment will
take about 1.5 hours.

There are 2 conditions in this study:

1) Participants receive a generalist treatment for personality problems, namely
GIT-PD
2) Participants receive specialist treatment for personality problems, namely
SFT or MBT

Both conditions do not deviate from regular care.

There are no risks associated with participating in this study. Much experience
has already been gained with the treatments provided, which shows that people
benefit from the treatment and that there are no special risks associated with
it. The treatments are also part of the institution's standard treatment
program. Therefore, no additional risks are associated with participating in
the study.
During the research there are several moments when participants have to
complete questionnaires. An interview is also conducted. It is estimated that
the starting measurement will take approximately 1,5 hours. The follow-up
measures at 3, 6, 12 and 24 months will take about half an hour, while the
measures at 18 months and at one year after completing treatment will take
about 1.5 hours.