What are the changes in the diagnosis of Other Specified Anxiety Disorder across the Diagnostic and Statistical Manual of Mental Disorders (DSM) versions III, III‑TR, IV, V, V‑TR and the International Classification of Diseases (ICD) versions X and XI?

Evolution of "Other Specified Anxiety Disorder" Across DSM and ICD Versions

Critical Terminology Clarification

The diagnostic category you are asking about—"Other Specified Anxiety Disorder"—did not exist as a formal entity until DSM-5 (2013), and the evidence provided does not directly address this specific residual category across all the versions you mention. However, I can trace the evolution of residual/unspecified anxiety categories based on the available evidence.

DSM-III Through DSM-IV Era: The "Not Otherwise Specified" Framework

DSM-III (1980)

• DSM-III introduced the first systematic classification of anxiety disorders by eliminating the overly broad "anxiety neurosis" category, which could not be reliably defined 1, 2.
• Generalized anxiety disorder was initially created as a residual category to capture anxiety states without spontaneous panic attacks—essentially functioning as the "catch-all" diagnosis when no other specific anxiety disorder fit 1, 2.
• The hierarchical exclusion structure in DSM-III prevented multiple anxiety diagnoses, forcing clinicians to use residual categories when presentations didn't cleanly match primary disorders 3.

DSM-III-R (1987)

• DSM-III-R revised exclusion criteria across anxiety disorders to reduce the rigid hierarchical structure that had forced overuse of residual categories 3.
• The revision allowed more concurrent diagnoses, theoretically reducing reliance on "NOS" (Not Otherwise Specified) categories, though the NOS designation remained available for atypical presentations 3.

DSM-IV (1994) and DSM-IV-TR (2000)

• DSM-IV maintained "Anxiety Disorder Not Otherwise Specified" as the residual category for clinically significant anxiety that did not meet criteria for any specific anxiety disorder 1.
• Research revealed that the NOS category was frequently misused—in one study of older veterans, only 3% of patients diagnosed with anxiety NOS actually had an unspecifiable anxiety disorder; 77% met full criteria for GAD, PTSD, panic disorder, or social anxiety disorder on structured interview 4.
• Cross-cultural studies found that approximately 60% of anxiety cases in Chinese populations fell into the NOS category when DSM-IV criteria were applied, suggesting that over-specification of symptom criteria excluded culturally variant presentations 5, 6.

DSM-5 (2013) and DSM-5-TR (2022): The Shift to "Other Specified"

Nomenclature Change

• DSM-5 replaced "Anxiety Disorder Not Otherwise Specified" with two distinct categories: "Other Specified Anxiety Disorder" and "Unspecified Anxiety Disorder" 7.
• "Other Specified" requires the clinician to document the specific reason the presentation does not meet criteria (e.g., "limited-symptom panic attacks"), whereas "Unspecified" is used when the clinician chooses not to specify the reason or lacks sufficient information 7.

Structural Improvements

• DSM-5 eliminated the requirement that adults recognize their anxiety as excessive or unreasonable, acknowledging that insight varies and reducing one source of diagnostic ambiguity 7, 6.
• Terminology was standardized (e.g., "fear response" replaced "anxiety response"; "not restricted to another mental disorder" replaced "not better accounted for") to improve inter-rater reliability 7, 6.
• DSM-5-TR retained the DSM-5 structure but provided textual clarifications without changing diagnostic thresholds 6.

ICD-10 (1992): Categorical Structure Without Residual Emphasis

• ICD-10 employs a purely categorical system with 11 disorder groupings in the mental and behavioral disorders chapter, without dimensional qualifiers 8.
• ICD-10 places greater emphasis on somatic symptoms (muscle tension, gastrointestinal upset) than DSM-IV's focus on psychological worry, leading to different diagnostic thresholds and potentially fewer cases falling into residual categories in populations with somatic presentations 6.
• The ICD-10 framework does not explicitly highlight "other specified" categories in the same manner as DSM; instead, it uses codes like F41.8 ("Other specified anxiety disorders") and F41.9 ("Anxiety disorder, unspecified") as administrative placeholders 6.

ICD-11 (2022): Dimensional Expansion and Harmonization

Structural Overhaul

• ICD-11 expanded to 21 disorder groupings and consolidated anxiety and fear-related disorders into a unified category spanning the lifespan 8.
• The separate childhood-onset grouping was eliminated, redistributing disorders to emphasize developmental continuity and reducing the need for age-specific residual categories 8.

Dimensional Qualifiers

• ICD-11 introduced dimensional qualifiers that can be attached to depressive episodes and other disorders, allowing clinicians to specify panic-attack features, anxiety specifiers, melancholic features, and seasonal patterns alongside categorical diagnoses 8.
• This dimensional approach reduces reliance on residual categories by permitting clinicians to code primary disorders with anxiety features rather than defaulting to "other specified" diagnoses 8.

Clinical Utility

• Approximately 83% of clinicians rate ICD-11 as easy to use, accurate, and clear in routine practice, with high inter-rater reliability for most disorders (though moderate for mood disorders) 8.
• The harmonization efforts between WHO and APA influenced both ICD-11 and DSM-5 structures, promoting cross-system consistency and reducing diagnostic discrepancies that previously inflated residual category use 8.

Key Clinical Pitfalls

• Misdiagnosis is rampant: The majority of "anxiety NOS" or "other specified" diagnoses represent missed specific anxiety disorders rather than truly atypical presentations, particularly when structured diagnostic interviews are not used 4.
• Cultural bias in criteria: DSM's prioritization of psychological over somatic symptoms systematically excludes culturally variant presentations, artificially inflating residual category use in non-Western populations 5, 6.
• Vague terminology: Terms like "marked," "persistent," and "excessive" in earlier DSM versions contributed to reliability problems; DSM-5's operationalization improved this but did not eliminate subjectivity 7.
• Duration thresholds: The 6-month requirement for youth (but not adults) creates diagnostic inconsistency and may push borderline cases into residual categories 7.

Practical Algorithm for Avoiding Residual Category Overuse

1. Always use a structured diagnostic interview (e.g., SCID) rather than unstructured clinical assessment to confirm whether specific anxiety disorder criteria are met 3, 4.
2. Screen systematically for panic disorder, GAD, social anxiety disorder, specific phobia, and agoraphobia using validated instruments (e.g., GAD-7 for initial screening) 7.
3. Assess cultural context: In patients from non-Western backgrounds, prioritize somatic symptom inquiry (muscle tension, gastrointestinal upset, autonomic arousal) over cognitive worry to avoid missing culturally variant presentations 6.
4. Apply dimensional qualifiers when using ICD-11: code the primary disorder (e.g., depressive episode) and add panic-attack or anxiety specifiers rather than defaulting to "other specified" 8.
5. Document the specific reason when using "Other Specified Anxiety Disorder" in DSM-5/5-TR (e.g., "limited-symptom panic attacks with agoraphobia") to facilitate treatment planning and avoid diagnostic ambiguity 7.