Avoidant personality disorder runs level with borderline across Norway
- A nationwide registry study published in Social Psychiatry and Psychiatric Epidemiology on 24 March 2026 followed 6,040,689 people, everyone born in 1940 or later resident in Norway at any point between 1 January 2010 and 31 December 2022. The Norwegian Population Registry, the Norwegian Patient Registry and KUHR, the health reimbursement database, were linked. Over at least 63,460,438 person-years the registers hold 61,077 first-time personality disorder diagnoses.
- The lifetime risk of receiving any ICD-10 personality disorder diagnosis in Norwegian specialist health care is 5.38% (95% CI 5.34, 5.43), 6.71% among women and 4.11% among men. Before the age of 18 the risk is 0.1%, and incidence peaks at 21.6 years.
- Avoidant personality disorder, F60.6, has a lifetime risk of 1.84% (1.81, 1.86); borderline, F60.3, has 1.77% (1.74, 1.79). Among men the two separate by a factor close to two: avoidant 1.42% (1.39, 1.45) against borderline 0.73% (0.71, 0.76). Among women borderline leads, 2.85% against 2.27%. No other specific diagnosis passes 0.5%.
- Between 2010 and 2022 first diagnoses of avoidant personality disorder rose fastest, with an incidence rate ratio of 1.66 (1.59, 1.74), ahead of mixed 1.48 and borderline 1.40. Seven categories fell over the same years, among them histrionic 0.51 and dissocial 0.75. Any personality disorder came to 1.21 (1.18, 1.24), which splits into 1.34 among women and 1.03 (0.99, 1.08) among men.
- What the registers hold are diagnoses as coded by treating clinicians in routine care, not diagnoses established by research interview. The authors write that the study describes phenomena particular to Norway, that its results depend on how Norwegian specialist services record a diagnosis, and that avoidant personality disorder is more widespread and dissocial personality disorder less widespread in Norway than in other countries for which data exist.
The study covers 6,040,689 people: everyone born in 1940 or later who was resident in Norway at some point between 1 January 2010 and 31 December 2022. Three national registers were linked for them, the population register, the Norwegian Patient Registry, into which every hospital is required to report each patient contact, and KUHR, through which health care is reimbursed. Norwegian specialist care spans psychiatric and somatic services, outpatient clinics and hospitals, child and adult provision, public and private clinics alike. Across at least 63,460,438 person-years those registers hold 61,077 first-time personality disorder diagnoses.
Eleven codes and their shares
Lifetime risk here is cumulative incidence from birth to age 82, the share of the population given a particular code at least once, with death and emigration treated as competing risks. For any personality disorder it comes to 5.38% (95% CI 5.34, 5.43), 6.71% among women and 4.11% among men.
Two codes carry most of that total, and the larger of them is not the expected one. Avoidant personality disorder stands at 1.84% (1.81, 1.86), borderline at 1.77% (1.74, 1.79). The gap widens among men, where avoidant reaches 1.42% (1.39, 1.45) and borderline 0.73% (0.71, 0.76). Among women the order reverses, 2.85% for borderline against 2.27% for avoidant. Then come the two codes that name no specific disorder: mixed at 1.18% and unspecified at 1.03%. Every remaining category stays under 0.5%, from paranoid at 0.43% down to histrionic at 0.04%. Peak incidence falls at 20.4 years for borderline and 23.0 for avoidant.
Change from 2010 to 2022
The rise over the period belongs to four diagnoses. Avoidant personality disorder moved by an incidence rate ratio of 1.66 (1.59, 1.74), mixed by 1.48, borderline by 1.40, anankastic by 1.29. Seven categories moved the other way, histrionic to 0.51, other specific to 0.64, unspecified to 0.68, dissocial to 0.75, dependent to 0.80, paranoid to 0.88, schizoid to 0.93. For any personality disorder the ratio is 1.21 (1.18, 1.24), and it separates by gender: 1.34 (1.30, 1.39) among women against 1.03 (0.99, 1.08) among men, an interval that includes one.
Set that pattern beside where the treatment literature sits. Trials, manuals, training courses and specialised services in personality disorder have been built around borderline, and the authors offer this as one reading of their own series: clinicians weigh how useful a diagnosis is, and borderline has come to be associated with relatively clearly defined treatment courses. In the Norwegian registers the diagnosis recorded most often is the other one.
Two boundaries belong with that number. The authors state that the study describes phenomena particular to Norway and cannot be carried directly across national contexts, and that avoidant personality disorder is recorded more widely there, dissocial less widely, than in the countries with comparable data. Danish estimates run close on the shared measures, 6.7% and 3.5% lifetime risk by gender against Norway’s 6.7% and 4.1%, though the Danish work did not estimate the specific diagnoses beyond borderline and dissocial. The second boundary is what the number is made of. These are codes entered by treating clinicians during routine contacts, so the series records diagnostic practice as much as it records patients.
Across the Norwegian population the lifetime risk of an avoidant personality disorder diagnosis is 1.84% against 1.77% for borderline, and among men it is 1.42% against 0.73%.
These are registered diagnoses, entered as ICD-10 codes by treating clinicians during routine contacts, and the authors write that their results depend on how Norwegian specialist services record a diagnosis. No structured research interview verified any of them. The study describes Norway, where avoidant personality disorder is recorded more widely and dissocial personality disorder less widely than in other countries with data, and the authors state it cannot be generalised directly to other national contexts. Incidence counts first diagnoses, so the decline in later life partly reflects a shrinking pool of people not yet diagnosed. ICD-10 was in use throughout the period, so nothing here speaks to ICD-11 severity or trait domains. The washout period for identifying earlier cases runs only four years, 2006 to 2009; extending it did not change the central estimates in a way consistent with substantial bias, but the authors do not rule out false first diagnoses. The registers carry no waiting times, no record of what treatment was given or completed, no outcomes and no measure of functional impairment. KUHR was used only to screen out prevalent cases, so primary care is not a source of diagnoses here.