What are the diagnostic changes for inhalant‑related disorders across the Diagnostic and Statistical Manual of Mental Disorders (DSM) versions III, III‑R, IV, V, V‑TR, and the International Classification of Diseases (ICD) versions X and XI?

Diagnostic Evolution of Inhalant-Related Disorders Across DSM and ICD Versions

Inhalant-related disorders have undergone minimal diagnostic changes across classification systems, with the most significant shift being DSM-5's rejection of inhalant withdrawal despite emerging evidence, while ICD-11 maintained structural reorganization without specific inhalant withdrawal criteria.

DSM Evolution: DSM-III Through DSM-5-TR

DSM-IV Framework

• DSM-IV established inhalant abuse and dependence as separate categorical diagnoses following the general substance use disorder framework, but explicitly excluded inhalant withdrawal as a diagnostic criterion based on expert opinion that withdrawal was neither common nor clinically significant 1.
• The abuse-dependence distinction in DSM-IV required three or more dependence criteria for dependence diagnosis, while abuse required one or more abuse criteria in the absence of dependence 2.

Critical DSM-5 Decision on Inhalant Withdrawal

• Despite accumulating evidence showing that approximately 47.8% of persons with inhalant dependence experienced three or more clinically significant withdrawal symptoms, the DSM-5 work group determined that evidence remained insufficient to include inhalant withdrawal in DSM-5 1.
• This decision contrasted sharply with cannabis withdrawal, which was added to DSM-5 based on similar evidence patterns, creating an inconsistency in the diagnostic approach 1.
• Research demonstrated that inhalant withdrawal symptoms were nearly as common as cocaine withdrawal symptoms among dependent users, yet this parallel was not deemed sufficient for inclusion 3.

DSM-5 Structural Changes

• DSM-5 merged abuse and dependence into a single "inhalant use disorder" diagnosis requiring two or more criteria from a combined list, eliminating the hierarchical abuse-dependence distinction 1.
• The threshold reduction from three criteria (dependence) to two criteria (use disorder) made the polysubstance dependence category obsolete and it was eliminated 1.
• DSM-5 renamed the chapter to "substance/medication-induced" disorders to explicitly include medications, and replaced "primary" with "independent" to clarify temporal relationships 4.
• A new requirement stipulated that substance-induced disorders must resemble full criteria for the corresponding psychiatric disorder, and the implicated substance must be pharmacologically capable of producing observed symptoms 4.

DSM-5-TR Continuity

• DSM-5-TR maintained the DSM-5 framework for inhalant use disorders without substantive changes to diagnostic criteria or the continued exclusion of inhalant withdrawal 5.

ICD Evolution: ICD-10 Through ICD-11

ICD-10 Structure

• ICD-10 classified inhalant-related disorders within the broader "Mental and Behavioural Disorders due to Psychoactive Substance Use" grouping, using 11 disorder groupings total in the mental disorders chapter 1.
• ICD-10 maintained a categorical approach without dimensional extensions for substance use disorders including inhalants 6.

ICD-11 Structural Reorganization (2019/2022)

• ICD-11 expanded from 11 to 21 disorder groupings in the Mental, Behavioral, or Neurodevelopmental Disorders chapter, organizing categories by shared etiology, pathophysiology, and phenomenology 1, 4, 6.
• The WHO eliminated the separate "childhood and adolescence" disorder grouping, integrating those conditions into broader categories to emphasize developmental continuity across the lifespan 1, 4, 6.
• Harmonization with DSM-5 was a central aim, shaping ICD-11's chapter structure and diagnostic terminology 1, 4, 6.

ICD-11 Dimensional Enhancements

• ICD-11 introduced dimensional severity ratings on a 4-point scale (0=absent, 1=mild, 2=moderate, 3=severe) for anxiety, depression, and cognitive domains, though these apply broadly rather than specifically to inhalant disorders 4, 6, 7.
• The system allows longitudinal coding of episode status (first, multiple, continuous) and current clinical state (symptomatic, partial remission, full remission) 4, 6, 7.

ICD-11 Clinical Utility Evidence

• Field studies with 928 clinicians showed 82.5%–83.9% rated ICD-11 as "quite" or "extremely" easy to use, representing significant improvement over ICD-10 4, 6, 7.
• ICD-11 demonstrated higher diagnostic accuracy, faster time to diagnosis, and greater perceived clinical utility compared with ICD-10 4, 6.
• Inter-rater reliability was high for psychotic disorders but only moderate for mood and anxiety-related disorders, indicating variable performance across diagnostic categories 4, 6, 7.

Persistent Limitations Across All Systems

Lack of Withdrawal Recognition

• Neither DSM-5/5-TR nor ICD-11 includes inhalant withdrawal as a formal diagnostic criterion, despite research showing nearly half of dependent users experience clinically significant withdrawal symptoms comparable to cocaine withdrawal 1, 3, 8.
• This omission persists even though withdrawal symptoms are associated with treatment-seeking behavior, difficulty quitting, and worse treatment outcomes 3, 8.

Categorical Versus Dimensional Debate

• Both DSM-5-TR and ICD-11 remain fundamentally categorical systems based on self-reported or clinically observable symptoms rather than underlying pathophysiology 1, 7.
• Item response theory analysis demonstrates that inhalant use disorders are best represented dimensionally rather than categorically, with no consistent hierarchical ordering of abuse and dependence criteria 2.
• The changes from ICD-10 to ICD-11 were relatively modest despite the extensive revision process, maintaining categorical foundations 1, 7.

Absence of Biological Validation

• Neither system has biological validation, resulting in biologically heterogeneous groups within the same diagnostic category 7.
• Laboratory testing for inhalant abuse remains very limited, and imaging studies provide only supportive rather than diagnostic information 5.

Clinical Implications

Comorbidity Screening Priority

• Adolescents with any history of inhalant use (with or without formal use disorder) require systematic screening for alcohol, hallucinogens, nicotine, cocaine, and amphetamine use disorders; major depression; suicidality; and physical/sexual abuse and neglect 9.
• The presence of inhalant use disorder does not significantly differ from inhalant use without disorder in terms of comorbidity burden, suggesting that any inhalant exposure warrants comprehensive assessment 9.

Multisystem Toxicity Assessment

• Inhalants cause multisystem damage affecting pulmonary, cardiac, dermatologic, renal, hematologic, gastrointestinal, hepatic, and neurologic systems, requiring thorough physical examination beyond psychiatric assessment 5.
• Chronic abuse produces psychiatric, cognitive, behavioral, and anatomical deficits that reduce productivity and quality of life 5.