The Influence of Treatment Format on Schema Therapy for Borderline Personality Disorder (IST-IGST)

April 29, 2026 updated by: Arnoud Arntz, University of Amsterdam

The Influence of Treatment Format on Effectiveness of and Dropout From Schema Therapy for Borderline Personality Disorder: Individual vs. Combined Individual Group Schema Therapy

The goal of this clinical trial is to compare etc. in patients with borderline personality disorder pure individual schema therapy to combined individual-group schema therapy. The main questions it aims to answer are:

  • is there a difference in effectiveness?
  • is there a difference in (early) treatment dropout?

Participants will receive either

  • individual schema therapy or
  • combined individual-group schema therapy.

Researchers will compare individual to combined individual-group schema therapy see if there is a difference in effects and/or a difference in dropout from treatment.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

Schema Therapy (ST) for Borderline Personality Disorder (BPD) was originally developed and tested as an individual treatment. Since 2009 group-ST became popular as an supposedly efficient alternative. A RCT found combined individual-group ST to be superior to predominantly group-ST. Thus, individual ST is important. The question arises how combined individual-group ST compares to purely individual ST. This study compares the two formats of ST in a multicenter randomized clinical trial (RCT). The primary outcomes are severity of BPD and (early) treatment dropout. Secondary outcomes include: measures of specific BPD-symptoms; schemas and schema-modes; general mental symptoms; general functioning; and happiness. Moderators hypothesized to predict what patient characteristics are related to differences in effectiveness between the 2 formats are also tested. At least 132 BPD patients from at least 2 sites will be randomized to combined individual-group ST or individual ST. Treatments will take 2 years. Assessments take place every 6 months, and 1 year after end of treatment.

Study Type

Interventional

Enrollment (Estimated)

132

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Netherlands
      • Amsterdam, Netherlands, 1001NK
        • Academic Center for Trauma and Personality ACTP
      • Amsterdam, Netherlands, 1093 MB
        • Arkin Mental Health Care
      • Helmond, Netherlands
        • GGZ Oost-Brabant

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • BPD as defined by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), assessed with the Structured Clinical Interview for the DSM-5 Personality Disorders (SCID-5-PD), as primary diagnosis
  • BPDSI total score ≥ 20 (i.e, severity in the BPD range, Giesen-Bloo et al., 2010)
  • Ability to understand, read, write and speak Dutch, or English if the site has research assistants and therapists of both conditions that are sufficiently fluent in English, as well as an English ST group (as at ACTP).

Exclusion Criteria:

  • DSM-5 substance use disorder that needs clinical detox according to the clinical staff (after 6 weeks of abstinence participation is possible).
  • Comorbid psychotic disorder (patients with temporary psychotic problems falling under BPD criterion 9 are not excluded)
  • DSM-5 Bipolar disorder, type 1 (current or past)
  • Acute suicide risk
  • Intelligence Quotient (IQ) < 80
  • Serious neurological problems such as dementia
  • Patients should not start with any form of psychological treatment during screening or during the study's waitlist or treatment. (Low frequency supportive treatment may be continued during wait and screening, but not during the study treatment.)
  • Not able or willing to plan participation in the treatment sessions. Note 1. In case of suspicion of exclusion criteria that need specific assessment, like IQ and dementia, a formal diagnostic assessment needs to be done before in/exclusion can be decided.

Note 2. No other psychological treatment during the study follow-up period is provided, unless this is necessary (clinical judgment). The 1 year treatment-free follow-up period is part of the treatment protocol, to help patients gain experience with life without mental health care. After 1 year further treatment can be offered, if indicated.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Individual Schema Therapy (IST)
IST will follow the revised protocol described by Arntz & van Genderen. In the first year, 2 sessions (of 50-60 minutes each) per week will be provided, with at least one day in between. In the second year, the frequency will be reduced to once a week for the first 6 months, for the next 3 months to once every two weeks, and for the last 3 months three (booster) sessions will be offered. Therapists need to be trained at least at the junior level of the Dutch ST Association, or of the International ST society (ISST), or having successfully completed the basic IST training and delivering the trial treatments under supervision of a recognized ST supervisor.
Behavioral: Individual Schema Therapy (IST)
IST is a form of empirically supported specialized psychotherapy for personality disorders. It is delivered in individual sessions by trained therapists.
Active Comparator: Combined Individual-Group Schema Therapy (IGST)

In IGST individual sessions (45-60 min) are provided weekly in the first year, and once every 2 weeks in the first three quarters of the second year, after which 3 monthly booster sessions are offered. Group sessions take place once per week for 1.5 years. After 1.5 years, patients leave the group but continue with IST during the last .5 year. If slots are available, new patients can enter the ST group every 10 weeks.

GST is provided as semi-closed group format developed from the closed format as developed by Farrell & Shaw. IST is based on Arntz & van Genderen, with the addition that IST and GST are coordinated at weekly peer supervision meetings, and that problems related to the patient's participation in the group are put on the IST agenda.

GST therapists don't need to be IST therapist of their patients. The same training requirements hold as in the IST arm. Additionally, GST-therapists completed GST training and receive(d) at least 10 GST supervisions.
Behavioral: Individual-Group Schema Therapy (IGST)
IGST is a form of empirically supported specialized psychotherapy for personality disorders. It is delivered in the combination of individual sessions and group therapy sessions by trained therapists.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Borderline Personality Disorder Severity
Time Frame: 0, 6,12,18, 24 and 36 months
The severity of manifestations of Borderline Personality Disorder during the last 3 months, assessed with a semi-structured clinical interview, the Borderline Personality Disorder Severity Index 5 (BPDSI-5), by an independent trained rater, blind for treatment arm. Minimum score is 0; maximum is 90; higher scores mean worse outcome.
0, 6,12,18, 24 and 36 months
Early treatment dropout rate
Time Frame: 6 months
Rate of dropout from treatment within the first 6 months
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Severity of each of the 9 BPD criteria
Time Frame: 0, 6,12,18, 24 and 36 months
Severity of separate BPD criteria will be assessed with the subscales of the Borderline Personality Severity Index 5 (BPDSI-5). Each subscale has a range from 0 to 10, higher scores mean worse outcomes.
0, 6,12,18, 24 and 36 months
Suicidality
Time Frame: 0, 6,12,18, 24 and 36 months
Suicidality will be assessed by the pertinent criterion 5 items of the Borderline Personality Disorder Severity Index 5 (BPDSI-5). The range is 0-10, higher scores mean worse outcomes.
0, 6,12,18, 24 and 36 months
Number of suicide attempts
Time Frame: 0, 6,12,18, 24 and 36 months
Number of suicide attempts during the last 3 months will be assessed by item 5.13 of the Borderline Personality Disorder Severity Index 5 (BPDSI-5). The minimum is 0, the maximum is not defined. Higher scores mean worse outcomes.
0, 6,12,18, 24 and 36 months
Subjective burden of Borderline Personality Disorder
Time Frame: 0, 6,12,18, 24 and 36 months
The subjective burden of Borderline Personality Disorder will be assessed with the Borderline Personality Disorder Checklist (BPDCL). The range is 47-235, higher scores mean worse outcome.
0, 6,12,18, 24 and 36 months
General psychopathology symptoms
Time Frame: 0, 6,12,18, 24 and 36 months
General psychopathology symptoms will be assessed with the Brief Symptom Inventory (BSI). The range is 0-4, higher scores mean worse outcome.
0, 6,12,18, 24 and 36 months
General, social, and societal functioning
Time Frame: 0, 6,12,18, 24 and 36 months
General, social, and societal functioning will be assessed with the World Health Organization Disability Assessment Schedule (WHODAS), taken by the research assistant who is blind for condition. The minimum score is 0, the maximum 100. Higher scores mean worse outcome.
0, 6,12,18, 24 and 36 months
Happiness
Time Frame: 0, 6,12,18, 24 and 36 months
Happiness is assessed with the 1-item happiness question validated in more than 30 countries. Range is 1-7, higher scores mean better outcomes.
0, 6,12,18, 24 and 36 months
Early Maladaptive Schemas
Time Frame: 0, 6,12,18, 24 and 36 months
Early Maladaptive Schemas will be assessed with the Young Schema Questionnaire short form (YSQ-SF). The range is 90-540; higher scores mean worse outcomes.
0, 6,12,18, 24 and 36 months
Schema Modes
Time Frame: 0, 6,12,18, 24 and 36 months
Schema Modes will be assessed with the Schema Mode Inventory (SMI). The minimum of the dysfunctional mode score is 123, the maximum 738, with higher scores meaning worse outcomes. The minimum of the functional modes score is 20, the maximum 120, with higher scores meaning better outcomes.
0, 6,12,18, 24 and 36 months
Number of medications used
Time Frame: 0, 6,12,18, 24 and 36 months
Medication use will be monitored during treatment and at each assessment. The minimum number is zero; the maximum is not defined. Higher numbers mean worse outcomes.
0, 6,12,18, 24 and 36 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Amsterdam

Collaborators

Ggz Oost Brabant
Academic Center for Trauma and Personality
Arkin Mental Health Care

Investigators

  • Principal Investigator: Arnoud Arntz, PhD, University of Amsterdam
  • Principal Investigator: Sophie Rameckers, MSc, University of Amsterdam

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 10, 2023

Primary Completion (Estimated)

August 30, 2030

Study Completion (Estimated)

August 30, 2030

Study Registration Dates

First Submitted

August 3, 2023

First Submitted That Met QC Criteria

August 3, 2023

First Posted (Actual)

August 14, 2023

Study Record Updates

Last Update Posted (Actual)

May 6, 2026

Last Update Submitted That Met QC Criteria

April 29, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FMG-4449-2023

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Given Dutch and European Union legal data protection regulations sharing individual data with other researchers can only be considered if other researchers can guarantee meeting strict conditions.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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