What are the strengths and weaknesses of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) and the International Classification of Diseases, Eleventh Revision (ICD-11) in diagnosing cannabis-related disorders?

Comparative Strengths and Weaknesses of DSM-5-TR and ICD-11 for Cannabis-Related Disorders

The DSM-5-TR offers superior sensitivity for identifying mild cannabis use disorder through its lower two-criterion threshold, while ICD-11 provides greater specificity by maintaining dependence as a distinct category, though this risks missing clinically significant sub-threshold cases. 1

DSM-5-TR Strengths

Unified Dimensional Framework

• The DSM-5-TR merged abuse and dependence into a single "Cannabis Use Disorder" (CUD) with 11 criteria, eliminating the problematic abuse/dependence dichotomy that lacked validity in DSM-IV. 1, 2
• This unified approach is based on data from over 200,000 participants and factor analyses demonstrating all criteria form a single unidimensional continuum. 3, 1, 2
• The dimensional severity grading (mild: 2-3 criteria, moderate: 4-5 criteria, severe: ≥6 criteria) provides systematic gradation of disorder severity. 1, 2

Enhanced Criterion Validity

• The addition of "craving" as a new criterion strengthens diagnostic accuracy, as factor analysis confirmed it belongs on the same unidimensional continuum as other criteria. 3, 1
• The removal of the "legal problems" criterion improved validity, as this criterion did not contribute to the unidimensional structure. 1
• Cannabis withdrawal was formally added after converging preclinical, clinical, and epidemiological evidence demonstrated its reliability, validity, pharmacological specificity, and clinical significance. 3, 1

Broader Case Identification

• The two-criterion threshold captures a broader population than traditional dependence thresholds, potentially identifying individuals who would be missed by ICD-11 criteria. 1, 2
• Approximately one-third of regular users in the general population and 50-95% of heavy users in treatment settings report withdrawal symptoms, which are now formally recognized. 3, 1
• Implementation is easier than DSM-IV because only one disorder is involved instead of two hierarchical disorders. 3

DSM-5-TR Weaknesses

Risk of Over-Diagnosis

• The lower two-criterion threshold may capture individuals with clinically insignificant problems, potentially leading to false-positive diagnoses compared to ICD-11's dependence-focused approach. 1, 2
• Mild CUD (2-3 criteria) shows weaker associations with psychiatric disorders and social impairment compared to severe CUD, raising questions about clinical significance at the lower threshold. 4
• Agreement between DSM-5 and ICD-10/DSM-IV is excellent (κ ≥ 0.9) for severe cases but declines for mild presentations where thresholds diverge. 1, 5

Limited Validation for Mild Severity

• Mild and moderate CUD are primarily associated with cannabis-specific validators (days used, self-reported problems, craving) but not consistently with broader psychopathology or functional impairment. 4
• Longitudinal studies examining outcomes (mortality, morbidity, quality of life) across the mild severity range are needed to validate the clinical significance of the lower threshold. 2

Diagnostic Concordance Issues

• Concordance between DSM-5 and ICD-11 ranges from good for severe cases to poor for comparisons of mild DSM-5 CUD and ICD-11 harmful use, due to fundamentally different conceptual approaches. 6, 5
• DSM-5 appears to capture a different aspect of problematic use and selects a different group of individuals compared to ICD-10, ICD-11, and DSM-IV. 6

ICD-11 Strengths

Preserved Dependence Syndrome Validity

• ICD-11 maintains substance dependence as the "master diagnosis," preserving the well-validated dependence syndrome concept that demonstrated consistently high reliability and validity in DSM-IV. 2
• The dependence-focused approach offers greater specificity and reduces false-positive diagnoses compared to DSM-5-TR's lower threshold. 1, 2
• Field studies demonstrated higher reliability and clinical utility of ICD-11 compared to ICD-10, reflecting the largest participative development process in classification history. 1, 2

Categorical Clarity with Dimensional Options

• ICD-11 retains harmful use and dependence as separate categories, providing clinically meaningful distinctions with empirical support. 2
• Optional dimensional assessments for certain disorders allow for more nuanced symptom profiles that inform treatment in specialized settings and research. 7
• The Clinical Descriptions and Diagnostic Guidelines provide detailed descriptions regarding core symptoms, differential diagnosis, and boundaries with normal functioning. 7

Excellent Concordance with Traditional Systems

• Classification of cannabis use disorders in ICD-11 shows almost perfect agreement with ICD-10 and DSM-IV (all κ ≥ 0.9). 1, 5
• Among regular cannabis users, 9.3% met criteria for ICD-11 harmful use and 3.2% for dependence, rates similar to ICD-10 and DSM-IV dependence. 5

ICD-11 Weaknesses

Risk of Under-Diagnosis

• ICD-11's narrower diagnostic net may overlook clinically significant sub-threshold problems that would be captured by DSM-5-TR's two-criterion threshold. 1
• A patient meeting DSM-5-TR criteria for mild CUD may not meet any ICD-11 diagnostic category, necessitating careful cross-system interpretation. 1

Dependence Over-Diagnosis in Adolescents

• In treated adolescents, proposed ICD-11 cannabis dependence prevalence was significantly higher compared to DSM-IV, DSM-5, and ICD-10 (p < 0.01), generating potential "false-positive" cases. 8
• Youth typically met ICD-11 dependence criteria by reporting tolerance and time spent using rather than impaired control over use, highlighting conceptual issues in the dependence algorithm. 8

Limited Validation of "Harm to Others" Feature

• Very low endorsement rates were observed for the new ICD-11 harmful use feature "harm to others," and diagnostic validity of self-reported harm to others is questionable. 5

Common Pitfalls and Clinical Implications

Cross-System Interpretation

• Clinicians must recognize that DSM-5-TR mild CUD and ICD-11 harmful use show poor concordance and capture different populations; diagnostic decisions should not assume equivalence. 6, 5
• Withdrawal symptoms can be misattributed to anxiety or depression if clinicians do not obtain a detailed substance-use timeline. 1
• The absence of withdrawal symptoms does not exclude a CUD diagnosis in DSM-5-TR because only two criteria are required, whereas ICD-11 dependence generally requires neuroadaptation features. 1

Treatment Planning Considerations

• Severe CUD (≥6 criteria) is associated with validators across all domains—cannabis use, psychopathology, and social impairment—and likely requires more intensive treatment to bolster physical, psychiatric, and social functioning. 4
• Mild and moderate severity thresholds provide useful information for identifying less severe disorders for prevention and brief intervention, though their long-term clinical significance requires further validation. 4
• The choice of classification system may depend on the clinical population of interest: DSM-5-TR for broader screening and early intervention, ICD-11 for more severe, treatment-seeking populations. 6