From healthy to disordered: An ICD-11 approach to assessing and understanding personality
By Dr Laura Porter, Clinical Assessment Psychologist
Regardless of the population you work with, the service you work in and your professional background, effective and meaningful outcomes are dependent on a strong, therapeutic relationship.
Connection is central to building a rapport and through understanding someone’s personality, a deeper and more comprehensive conceptualisation of the individual can emerge. This, in turn, supports the diagnostic understanding and informs the treatment approach1.
‘Personality is something and does something’ (Allport, 1937)
Allport’s definition of personality captures the importance of looking beyond the behaviour and the impression it makes on others. He highlights that ‘it is what lies behind specific acts and within the individual’ with a need to focus on ‘what the personality is’ and ‘what the personality does2.’
A reliable, valid, clinically applicable approach
The development and release of ICD-113 led to a significant shift in how personality disorders are conceptualised. Compared to its categorical predecessor, the ICD-11 classification provides a dimensional approach to understanding an individual’s personality along a continuum from subthreshold difficulties through to a severe personality disorder.
The ICD-11 framework supports a flexible approach to understanding personality functioning, which acknowledges the heterogeneity within a diagnostic label. By capturing both overall severity and specific trait expressions, the ICD-11 systematically evaluates an individual’s personality. The global evaluation alongside assessment of trait-specifiers supports not only the case conceptualisation but also treatment planning and management decisions.
The continuum approach supports a destigmatised view of personality disorders4, which is extremely valuable for clinicians when seeking to develop and establish therapeutic rapport. The ICD-11 framework guides clinicians from understanding personality traits to changing personality functioning for an individual. Such a conceptualisation is valuable in continuing to build the evidence challenging the view that personality disorders cannot be treated and in turn reducing the associated stigma of such a diagnosis5.
Introducing the DIPP-11: The first purpose-built ICD-11 interview for assessing personality disorders
The Diagnostic Interview for Personality Pathology based on ICD-11 (DIPP-11)6 is a semi-structured, clinician-administered interview for ICD-11 personality disorders, fully aligned with the diagnostic framework. Developed by Bo Bach and Martin Sellbom, the DIPP-11 provides a comprehensive evaluation of personality disorder presence, severity and related traits, including subthreshold personality difficulties, supporting a holistic clinical formulation rather than a checklist-based diagnosis.
Its alignment with the ICD-11 supports clinicians to establish an understanding of an individual that facilitates differential diagnoses.
- Are they experiencing personality difficulties or do they meet the criteria for a personality disorder?
and/or
- Is this individual experiencing a mental health difficulty?
and/or
- Do they have an underlying neurodevelopmental condition?
In the presence of significant overlap between mental health disorders, neurodevelopmental conditions and personality dysfunction, the DIPP-11 enables you to ask and access the answers to such questions.
Meet Ben
Ben is one of several case studies provided to clinicians within the accompanying User Guide for the DIPP-11. Each case study demonstrates the way in which the DIPP-11 can be used to understand individuals across the continuum from healthy to disordered personality functioning, and support in making differential diagnoses and support treatment planning.
(The following provides a summary of one of the case studies included within the DIPP-11 User Guide as an example of an individual who was diagnosed using the DIPP-11 with a Moderate Personality Disorder; the case study in its entirety is available within the User Guide).
Ben is a 25-year-old financial adviser referred for a pre-sentence psychological assessment following charges linked to stalking and repeated harassment of a colleague. The referral indicated Ben pleaded guilty ‘just to make it go away,’ denying any responsibility.
Ben was described as a confident, ambitious individual with a history suggestive of longstanding difficulties with interpersonal relationships, empathy, accountability, and managing frustration. Ben tends to dismiss the impact of his behaviour on others, views criticism as unfair, and is frequently involved in conflict, with this apparent from a young age. Multiple occasions of acting impulsively were documented, including at times of irritability or in response to feeling challenged.
Given the enduring nature of these difficulties across multiple areas of functioning, a comprehensive personality assessment would help to better understand Ben’s personality functioning, interpersonal style, emotional regulation, and personality traits that may be contributing to his behaviour. This information could support formulation, risk assessment, treatment planning, and recommendations to the court.
References
1. Bach, B., & Simonsen, S. (2025). ICD-11 personality disorders: A clinician's guide. Hogrefe Publishing.
2. Allport, G.W. (1937). Personality: A psychological interpretation. University of Michigan.
3. World Health Organization. (2019). International statistical classification of diseases and related health problems (11th ed.). https://icd.who.int/
4. Stricker, J., Hasenburg, L., Jakob, L., Weigl, T. & Pietrowsky, R. (2024). Public stigma and continuum beliefs across personality disorder severity levels. Journal of Personality Disorders, 38(1), 75-86. https://doi.org/10.1521/pedi.2024.38.1.75
5. Royal College of Psychiatrists. (2020, January 9). Challenge the myth that personality disorder can't be treated, urge psychiatrists. https://www.rcpsych.ac.uk/news-and-features/latest-news/detail/2020/01/09/challenge-the-myth-that-personality-disorder-can't-be-treated-urge-psychiatrists
6. Bach, B. & Sellbom, M. (2025). Diagnostic Interview for Personality Pathology in ICD-11 (DIPP-11). Hogrefe Publishing.
Register for the DIPP-11 webinar
Sign up for the upcoming DIPP-11 webinar on Thursday 12th November at 9am (GMT) facilitated by the authors themselves, Bo Bach and Martin Sellbom.
Order the DIPP-11 and related book from our webshop
Dr Laura Porter
Dr Laura Porter is a Clinical Assessment Psychologist who joined Hogrefe UK in April 2026. After qualifying as a Clinical Psychologist in 2020, she worked in a multi-disciplinary NHS CAMHS team, providing assessment, intervention and system-wide consultation (and so much more!). Since completing ADOS-2 and ADI-R training in 2023, she regularly conducts neurodevelopmental assessments and provides post-diagnostic support for children and families. Professional interests include children's social, emotional and mental wellbeing, trauma, neurodiversity, and systemic approaches. From early career roles in forensic settings, Dr Porter also holds an interest in forensic mental health. She is motivated to improve the understanding and support for young people by both developing and implementing evidence-based practice, reflecting her passion for supporting young people to reach their potential and thrive.
