A Somatic Ontology for Computational Therapeutics: Formalizing Body-Based Experience for Digital Mental Health

This paper introduces the Cathexis Somatic Ontology (CSO), the first formal vocabulary and relational schema for encoding body-based therapeutic experience computationally. The CSO defines entity classes for 24 anatomical zones, 15 sensation qualities, 16 neurobiological organization patterns (territories), 3 memory-system-based change mechanisms, 7 intervention mechanism types, and a network visualization ontology -- all organized within a Markov blanket framework derived from Friston's free energy principle. Cross-mappings to ICD-11, SNOMED CT, and HL7 FHIR are provided. The ontology integrates six major research programs: constructed emotion theory (Barrett), predictive processing (Friston), affective neuroscience (Panksepp), somatic markers (Damasio), neuropsychoanalysis (Solms), and memory reconsolidation (Kandel, Nader, Schiller, Ecker). Published under CC BY-NC-SA 4.0. Machine-readable representations (JSON-LD, OWL) planned for v1.1.