Evolution of Catatonia Diagnosis Across DSM and ICD Classifications
Catatonia has undergone a fundamental reconceptualization from being exclusively a schizophrenia subtype in early classifications to an independent syndrome with multiple diagnostic contexts in modern systems, with ICD-11 and DSM-5-TR now recognizing it as a specifier across psychiatric disorders and as a standalone diagnosis. 1, 2
Historical Context: DSM-III Through DSM-III-R (1980-1994)
DSM-III and DSM-III-R defined catatonia exclusively as a subtype of schizophrenia (295.2), despite clinical evidence showing catatonic symptoms occurred prominently in affective disorders, systemic illnesses, and neurotoxic states. 3
This narrow classification led to systematic misdiagnosis, with studies showing that among patients initially diagnosed with schizophrenia, catatonic type, only 37% actually had schizophrenia on discharge—the remainder had affective disorders (37%) or organic affective disorders (26%). 3
The restriction to schizophrenia in DSM-III/III-R had no clinical or research justification and confused treatment options, as catatonia responds rapidly to benzodiazepines and ECT regardless of underlying condition. 4
Major Shift: DSM-IV (1994)
DSM-IV introduced "catatonia secondary to a general medical condition" as a new codable diagnosis, marking the first recognition that catatonia extends beyond schizophrenia. 5
DSM-IV added catatonia as an episode specifier for major mood disorders, though without separate coding capability. 5
A critical limitation emerged: DSM-IV used different diagnostic criteria sets for catatonia in schizophrenia versus neurological/medical conditions, creating diagnostic inconsistency. 5
Catatonia remained a codable subtype of schizophrenia but only a non-codable specifier for mood disorders, contributing to continued under-recognition by clinicians. 5
Comprehensive Expansion: DSM-5 and DSM-5-TR (2013-2022)
DSM-5 implemented four major changes: (1) a single unified set of criteria for catatonia across all diagnoses, (2) catatonia as a codable specifier for both schizophrenia and major mood disorders, (3) catatonia as a specifier for other psychotic disorders (schizoaffective, schizophreniform, brief psychotic, substance-induced), and (4) a new "catatonia not otherwise specified" category for rapid diagnosis when the underlying condition is unclear. 5
These changes aimed to improve consistent recognition across psychiatric disorders and facilitate specific treatment. 5
DSM-5-TR requires at least 3 symptoms from 12 possible features including stupor, catalepsy, waxy flexibility, mutism, negativism, posturing, mannerisms, stereotypies, agitation, grimacing, echolalia, and echopraxia. 1, 6
ICD Evolution: ICD-10 to ICD-11
ICD-10 Limitations
ICD-10 maintained the outdated view of catatonia primarily as a form of schizophrenia, similar to ICD-9 and earlier versions. 2
ICD-10 introduced "organic catatonic disorder" but failed to incorporate growing evidence that catatonia occurs in mood disorders and autism-spectrum disorders. 2
The classification system had only 11 disorder groupings and maintained traditional categorical classification without dimensional assessments. 7, 8
ICD-11 Revolutionary Changes (2022)
ICD-11 conceptualizes catatonia as an independent disorder with a common clinical phenotype regardless of associated condition, representing a fundamental paradigm shift. 1, 2
ICD-11 requires at least 3 clinical features from three categories: decreased psychomotor activity, increased psychomotor activity, or abnormal psychomotor activity—features may come from any combination, but only one from the increased activity category should be counted. 2
ICD-11 establishes four distinct catatonia diagnoses: (1) catatonia associated with another mental disorder, (2) catatonia induced by substances or medications, (3) secondary catatonia syndrome, and (4) catatonia, unspecified. 2
The ICD-11 mental, behavioral, and neurodevelopmental disorders chapter expanded from 11 to 21 disorder groupings, with field studies demonstrating higher reliability and clinical utility compared to ICD-10. 1, 8
ICD-11 provides explicit guidance on distinguishing catatonia from similar behavioral features including psychomotor retardation in depression, delirium, and factitious disorder. 2
Current Alignment and Remaining Discrepancies
ICD-11 and DSM-5-TR are broadly aligned in which items are included and item definitions, representing the closest convergence in catatonia diagnosis across classification systems. 6
Both systems recognize catatonia across multiple psychiatric and medical conditions, moving away from the schizophrenia-centric view. 2, 5
A fundamental limitation persists in both systems: the lack of specific item thresholds for individual features, which can introduce variance in caseness determination. 6
DSM-5-TR requires 3 of 12 features, while ICD-11 requires 3 features from specific psychomotor categories with the restriction on increased activity symptoms—this represents a subtle but meaningful difference in diagnostic approach. 2, 6
Clinical Implications of Classification Changes
The expanded recognition of catatonia beyond schizophrenia should improve detection rates, as catatonia occurs in approximately 10% of psychiatric hospital admissions across mood disorders and toxic states. 4
The unified criteria across conditions in both modern systems facilitate rapid diagnosis and specific treatment with benzodiazepines or ECT, which achieve remission quickly regardless of underlying etiology. 4
The addition of "catatonia not otherwise specified" in DSM-5 and "catatonia, unspecified" in ICD-11 allows immediate treatment initiation in severely ill patients before the underlying diagnosis is established—a critical advancement for reducing morbidity and mortality. 2, 5