{
  "abstract": "Background: Schema therapy (ST) is proven to be effective for cluster-C personality disorders (PDs). Recently, a group format of ST (GST) has gained popularity but has not been compared with other treatments.\n\nObjective: To compare the effectiveness of GST to individual ST (IST) and specialised treatment as usual (sTAU) for cluster-C PDs.\n\nMethod: We conducted a multicentre parallel-group, randomised controlled trial (QUalitative and Effectiveness Study to select optimal Treatment for Cluster-C PD) comparing 1 year of GST and IST with open-ended sTAU, with a follow-up assessment 2 years after start of treatment. Outpatients (>18 years) with a primary cluster-C PD were recruited and assigned to GST (30 weekly sessions plus 4 monthly booster sessions), IST (50 sessions with decreasing frequency) or sTAU (routine care in PD-specialised departments). The primary outcome was cluster-C PD severity change.\n\nResults: 369 participants (mean (SD) age, 37.24 (11.21) years; 242 (65.6) female) received GST (46.6%), IST (26.0%) or sTAU (27.4%). At 1 year, GST was superior to sTAU (d=0.33, 95% CI 0.05 to 0.61, p=0.02), and IST was superior to sTAU (d=0.41, 95% CI 0.10 to 0.72, p=0.010). GST and IST did not differ significantly (d=0.08, 95% CI −0.19 to 0.35, p=0.57). No significant differences were found at 2 years (GST-sTAU: d=0.12, 95% CI −0.18 to 0.42, p=0.44; GST-IST: d=0.11, 95% CI −0.18 to 0.39, p=0.46; IST-sTAU: d=0.23, 95% CI −0.11 to 0.56, p=0.18). Treatment retention in IST (92.7%) was superior to sTAU (78.2%) but did not differ significantly with GST (84.9%) at 1 year. At 2 years, treatment retention in IST and GST remained the same and was both superior to sTAU (72.3%).\n\nConclusion: Both GST and IST outperformed sTAU after 1 year, although differences were no longer evident at follow-up. GST and IST showed higher retention rates than sTAU.\n\nClinical implications: These findings support GST and IST as good treatment options for cluster-C PDs.\n\nTrial registration number: NL-OMON19942.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Clinical Psychology, University of Amsterdam, Amsterdam, The Netherlands",
    "Department of Psychological Methods, University of Amsterdam, Amsterdam, The Netherlands",
    "Department of Health Services Research, Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, The Netherlands",
    "Trimbos Institute, Utrecht, The Netherlands",
    "PsyQ Utrecht, Utrecht, The Netherlands",
    "PsyQ Zaandam, Zaandam, The Netherlands",
    "PsyQ Amsterdam, Amsterdam, The Netherlands",
    "PsyQ Rotterdam, Rotterdam, The Netherlands",
    "Academic Centre for Trauma and Personality, Amsterdam, The Netherlands",
    "IPGGZ Groningen, Groningen, The Netherlands",
    "IPGGZ Veendam, Veendam, The Netherlands",
    "Emergis, Goes, The Netherlands",
    "Department of Medical and Clinical Psychology, Tilburg University, Tilburg, The Netherlands",
    "Department of Personality Disorders, GGZ Oost Brabant, Helmond, The Netherlands"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 16,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Anne-Sophie S M Venhuizen",
      "orcid": "0009-0008-0718-7492"
    },
    {
      "affs": [
        0
      ],
      "name": "Iuno Z Groot",
      "orcid": "0000-0001-5744-4567"
    },
    {
      "affs": [
        1
      ],
      "name": "Raoul P P P Grasman"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Silvia M A A Evers"
    },
    {
      "affs": [
        4
      ],
      "name": "Joël R Van Aalderen"
    },
    {
      "affs": [
        4
      ],
      "name": "Mascha Nuijten"
    },
    {
      "affs": [
        5
      ],
      "name": "Elvan Tutkun"
    },
    {
      "affs": [
        5
      ],
      "name": "Susanne Dalmeijer"
    },
    {
      "affs": [
        6
      ],
      "name": "Kasper Nikkels"
    },
    {
      "affs": [
        7
      ],
      "name": "Myrte Maarschalkerweerd"
    },
    {
      "affs": [
        8
      ],
      "name": "Charlotte M E Van Ginkel"
    },
    {
      "affs": [
        9
      ],
      "name": "Agatha Ph Hollander"
    },
    {
      "affs": [
        10
      ],
      "name": "Fatima Jegić"
    },
    {
      "affs": [
        11
      ],
      "name": "Lotte Timmerman"
    },
    {
      "affs": [
        12,
        13
      ],
      "name": "Nathan Bachrach"
    },
    {
      "affs": [
        0,
        8
      ],
      "name": "Arnoud Arntz"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0y0rbh5h90f9j.bib",
  "cited_by": 0,
  "doi": "10.1136/bmjment-2026-302929",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13711618/",
  "id": "0y0rbh5h90f9j",
  "issns": [
    "2755-9734"
  ],
  "landing_url": "https://doi.org/10.1136/bmjment-2026-302929",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "1506"
    ],
    [
      "heading",
      "Original Research"
    ],
    [
      "heading",
      "Psychotherapies"
    ],
    [
      "openalex",
      "3203|Personality Disorders and Psychopathology"
    ]
  ],
  "openalex": "W7223660811",
  "pdf_url": "https://mentalhealth.bmj.com/content/29/1/e302929.full.pdf",
  "pmcid": "PMC13711618",
  "pmid": "42933862",
  "published": "2026-10-26",
  "publisher": "BMJ Publishing Group",
  "ris": "https://research.draconitic.com/paper/0y0rbh5h90f9j.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T12:22:22Z",
      "native_id": "PMC13711618",
      "source": "pmc",
      "url": "https://doi.org/10.1136/bmjment-2026-302929"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:3203|Personality Disorders and Psychopathology",
      "subfield": "psychiatry"
    }
  ],
  "title": "Quest for optimal treatment of cluster-C personality disorders: evaluating schema therapy formats in a multicentre randomised controlled trial",
  "title_text": "Quest for optimal treatment of cluster-C personality disorders: evaluating schema therapy formats in a multicentre randomised controlled trial",
  "type": "peer-reviewed",
  "updated_at": "2026-10-31T12:22:22Z",
  "url": "https://research.draconitic.com/paper/0y0rbh5h90f9j",
  "venue": "BMJ Mental Health",
  "versions": []
}