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

Comparative Analysis of DSM-5-TR and ICD-11 for Unspecified Catatonia

Both DSM-5-TR and ICD-11 represent significant improvements in catatonia diagnosis, but ICD-11 provides superior conceptual clarity by recognizing catatonia as an independent disorder with explicit diagnostic thresholds, while DSM-5-TR's "unspecified catatonia" category offers more practical flexibility for acute clinical situations where the underlying etiology remains unclear. 1, 2, 3

Strengths of ICD-11

Conceptual Framework

• ICD-11 conceptualizes catatonia as an independent disorder with a common clinical phenotype regardless of associated condition, representing a paradigm shift from viewing it exclusively as a schizophrenia subtype 1, 2
• The classification underwent the largest participative revision in classification history, with field studies demonstrating higher reliability and clinical utility compared to ICD-10 1
• ICD-11 expanded from 11 to 21 disorder groupings in the mental, behavioral, and neurodevelopmental disorders chapter, providing more comprehensive classification 1

Diagnostic Criteria

• ICD-11 requires at least 3 clinical features from three categories: decreased psychomotor activity, increased psychomotor activity, or abnormal psychomotor activity, with features from any combination but only one from the increased activity category 1, 2
• Provides explicit guidance on distinguishing catatonia from similar behavioral features including psychomotor retardation in depression, delirium, and factitious disorder 1, 2
• Offers four distinct catatonia diagnoses: catatonia associated with another mental disorder, catatonia induced by substances or medications, secondary catatonia syndrome, and catatonia unspecified 2

Strengths of DSM-5-TR

Clinical Utility

• DSM-5-TR includes a specific "catatonia not otherwise specified" (now "unspecified catatonia") category that allows for rapid diagnosis and specific treatment in severely ill patients when the underlying diagnosis is not immediately available 3, 4
• Uses a single set of criteria to diagnose catatonia across the diagnostic manual, improving consistency 3
• Catatonia functions as a codable specifier for schizophrenia, major mood disorders, and other psychotic disorders including schizoaffective disorder, schizophreniform disorder, brief psychotic disorder, and substance-induced psychotic disorder 3

Practical Application

• The unspecified category is particularly valuable for idiopathic cases consistent with Kahlbaum's concept of catatonia as a distinct disease state 4
• Facilitates immediate treatment initiation in life-threatening situations without requiring complete diagnostic workup 3, 4

Weaknesses of Both Systems

Lack of Operational Specificity

• Both DSM-5-TR and ICD-11 are broadly aligned in which items are included and item definitions, but the fundamental limitation is the lack of item thresholds 5
• Neither system provides clear, consistent definitions for catatonia features that are essential for reliable detection 5
• The absence of standardized assessment procedures contributes to catatonia remaining unrecognized in an unknown number of patients 6

Categorical Limitations

• Both systems remain primarily categorical, classifying mental phenomena based on self-reported or clinically observable symptoms rather than incorporating neurobiological dimensions 7
• Changes from ICD-10 to ICD-11 were relatively modest, with no paradigm shift toward biologically informed classification 7
• Neither system adequately addresses the biological heterogeneity within diagnostic categories 7

Assessment Gaps

• The many differences across catatonia rating scales and diagnostic criteria make it difficult for clinicians to know what catatonia looks like and what constitutes each feature 5
• Lack of standardized videographic resources and clinical assessment protocols in the diagnostic criteria themselves 5

Recommended Improvements for Clinical Work

Standardization of Assessment

• Incorporate the Bush-Francis Catatonia Rating Scale as the standard assessment tool, as it is the most efficient with a screening instrument, videographic resources, and standardized clinical assessment 5
• Alternatively, the Northoff scale offers the most detailed assessment and uniquely emphasizes emotional and volitional disturbances in catatonia 5
• Both scales can be converted to diagnostic criteria with limited modification 5

Enhanced Diagnostic Guidance

• Add specific item thresholds and operational definitions for each catatonia feature to reduce diagnostic discordance 5
• Include explicit guidance on duration requirements and severity gradations for each psychomotor feature 5
• Provide standardized training materials including video examples of each catatonia sign 5

Recommended Improvements for Research

Dimensional Approach

• Adopt a stepwise diagnostic approach that retains categorical classification for clinical utility but allows detailed dimensional assessments of psychopathology for research purposes 7
• Implement symptom profiles that provide specific information regarding domains of psychological malfunctioning beyond overall severity 7
• This approach combines advantages of categorical diagnosis for rapid communication with dimensional assessments for nuanced research characterization 7

Neurobiological Integration

• Incorporate Research Domain Criteria (RDoC) framework elements to provide biologically informed understanding, though RDoC alone is too complex for clinical practice 7
• Develop biologically more homogeneous subgroups within the catatonia diagnosis to improve treatment selection and earlier detection 7
• Link clinical manifestations to specific brain systems while maintaining clinically observable diagnostic criteria 7

Longitudinal Characterization

• Emphasize the prognostic and therapeutic significance of longitudinal course of illness in differentiating cases of catatonia, as better defined in the Wernicke-Kleist-Leonhard classification system 4
• Track treatment response patterns to different interventions (benzodiazepines, electroconvulsive therapy, NMDA antagonists, antipsychotics) across catatonia subtypes 6, 4

Critical Caveats

• Field studies evaluating ICD-11 may have selection bias, with practitioners positive toward ICD-11 more likely to participate 7
• Vignette-based studies describe prototypic cases that may not reflect real-life complexity 7
• Further ecological field studies are needed to reveal how well ICD-11 works under regular clinical conditions 7
• The efficacy of antipsychotics in some catatonia cases contradicts conventional guidelines, highlighting the need for better subtype differentiation 4