Describing the features of catatonia: A comparative phenotypic analysis

Background: Catatonia is widely under-detected, and the many differences across catatonia rating scales and diagnostic criteria could be a key reason why clinicians have a hard time knowing what catatonia looks like and what constitutes each of its features. Methods: This review begins by discussing the nature of catatonia diagnosis, its evolution in ICD and DSM, and different approaches to scoring. The central analysis then provides a descriptive survey of catatonia's individual signs across scales and diagnostic criteria. The goal of this survey is to characterize distinctions across scales and diagnostic criteria that can introduce variance into catatonia caseness. Results: Diagnostic criteria for catatonia in DSM-5-TR and ICD-11 are broadly aligned in terms of which items are included, item definitions and number of items required for diagnosis; however, the lack of item thresholds is a fundamental limitation. Many distinctions across scales and criteria could contribute to diagnostic discordance. Discussion: Clear, consistent definitions for catatonia features are essential for reliable detection. Of available scales, Bush-Francis and Northoff can be converted to diagnostic criteria with limited modification. Bush-Francis is the most efficient, with a screening instrument, videographic resources and standardized clinical assessment. Northoff offers the most detailed assessment and uniquely emphasizes emotional and volitional disturbances in catatonia. Conclusions: The field's understanding of the catatonia phenotype has advanced considerably over the past few decades. However, this review reveals many important limitations in the ICD and DSM as well as differences across scales and criteria that stand in the way of reliable catatonia detection.