What are the changes in the diagnosis of Delusional disorder across Diagnostic and Statistical Manual of Mental Disorders (DSM) (Diagnostic and Statistical Manual of Mental Disorders) versions 3, 3-TR (Text Revision), 4, 5, and 5-TR (Text Revision), and International Classification of Diseases (ICD) (International Classification of Diseases) versions 10 and 11?

Diagnostic Evolution of Delusional Disorder Across DSM and ICD Versions

Critical Note on Available Evidence

The provided evidence focuses primarily on delirium (not delusional disorder) and general ICD-10 to ICD-11 changes, with limited specific information on delusional disorder's diagnostic evolution across all requested versions. I will address what is available while noting significant gaps.

Key Diagnostic Changes Across DSM Versions

The diagnostic criteria for delusional disorder have undergone substantial modifications from DSM-III through DSM-5, with each revision significantly altering prevalence rates and clinical identification. 1

DSM-III to DSM-5 Evolution

• DSM-III was the most restrictive system, requiring a 6-month duration criterion that identified patients with more severe illness presentations, including higher rates of cluster A personality disorders, insidious onset, poor treatment response, chronic course, and worse psychosocial functioning 1

• DSM-5 became the most inclusive diagnostic system, capturing the largest number of patients (n=274 vs DSM-III's n=187 in one comparative study) 1

• The diagnostic criteria show poor to fair concordance across versions, meaning patients diagnosed under one system may not meet criteria under another 1

• Type of delusions (the specific subtype classification) had minimal impact on clinical validators across all DSM systems, suggesting this distinction may have limited clinical utility 1

DSM-5 Specific Changes

• DSM-5 eliminated schizophrenia subtypes and replaced them with dimensional symptom assessments, though specific details about delusional disorder criteria in DSM-5 versus DSM-IV are not detailed in the provided evidence 2

• DSM-5 revisions were driven by neuroscience advancements, clinical need, and efforts to align with ICD-11 3

ICD-10 vs ICD-11 Changes

ICD-10 Characteristics

• ICD-10 included a 3-month duration criterion for delusional disorder, which showed poor relationship to clinical validators (unlike DSM-III's 6-month criterion) 1

• ICD-10 classified delusional disorder within the broader category of "Mental and Behavioural Disorders" 4

ICD-11 Modifications

• ICD-11 was published in May 2019 and implemented January 1,2022 4

• The ICD-11 Mental, Behavioral or Neurodevelopmental Disorders (MBND) chapter expanded from 11 disorder groupings in ICD-10 to 21 disorder groupings 4

• ICD-11 eliminated the separate grouping for "mental and behavioral disorders with onset during childhood and adolescence," redistributing these disorders to emphasize developmental continuity across the lifespan 4

• ICD-11 introduced dimensional approaches alongside categorical diagnoses for some disorders, though specific application to delusional disorder is not detailed in the provided evidence 4

• ICD-11 reorganized acute and transient psychotic and delusional disorders, though specific criteria changes are not provided 2

Core Diagnostic Features (Consistent Across Systems)

Delusional disorder is distinguished from schizophrenia by the absence of marked deterioration in social, occupational, and self-care functioning, with relatively preserved functioning despite delusions. 5

• Characterized by one or more delusions with relative absence of other psychopathology, contrasting with schizophrenia which requires at least two psychotic symptoms 5

• The presence of "bizarre delusions" alone is sufficient for schizophrenia diagnosis in DSM-IV, but bizarre delusions are rare (2.56% prevalence in one Indian study) and culture-dependent 6

Clinical Implications and Pitfalls

Duration Criteria Matter Most

• The 6-month duration requirement (DSM-III) versus shorter durations (3 months in ICD-10, variable in other DSM versions) is the single most important factor differentiating severity and prognosis 1

• Longer duration requirements identify patients with more chronic, treatment-resistant presentations 1

Diagnostic System Non-Interchangeability

• Diagnostic criteria are not interchangeable—a patient meeting criteria under one system may not under another, affecting treatment access and research inclusion 1

• Clinicians should document which specific diagnostic system was used, as this has prognostic implications 1

Treatment Evidence Gap

• Despite international recognition in both ICD and DSM systems, there is insufficient high-quality randomized trial evidence for any specific treatment of delusional disorder 7

• Until better evidence emerges, offering treatments with efficacy in other psychotic disorders is reasonable 7

DSM-5-TR and Detailed ICD-11 Delusional Disorder Criteria

The provided evidence does not contain specific information about DSM-5-TR changes or detailed ICD-11 delusional disorder criteria. The evidence focuses on general structural changes to classification systems rather than disorder-specific modifications for delusional disorder.