Dimensional and Network Architecture of Catatonia in Schizophrenia Spectrum Disorders and Mood Disorders: Evidence from a Large, Deeply Phenotyped Sample.

BACKGROUND AND HYPOTHESIS: Catatonia is a transdiagnostic syndrome in schizophrenia spectrum disorders (SSD) and mood disorders (MOD), but both its empirical structure and the frequency of its signs and symptoms remain insufficiently understood. STUDY DESIGN: We examined 465 patients with SSD or MOD from Mannheim (Germany) and Bern (Switzerland) using the 40-item Northoff Catatonia Rating Scale (NCRS); 336 patients were additionally assessed with the Bush-Francis Catatonia Rating Scale (BFCRS). We examined the frequency of catatonia signs and symptoms across subthreshold and syndromal presentations (ICD-11, DSM-5) and analyzed the relationships between signs and symptoms using network analysis. STUDY RESULTS: 84.1% of patients exhibited at least 1 catatonia sign or symptom, and 65.8% 3 or more on the NCRS, with 86 patients (18.5%) meeting ICD-11 criteria and 26 (5.6%) fulfilling DSM-5 criteria based on overlapping NCRS items. In the BFCRS subsample, 26.8% of patients showed at least 1 sign or symptom, and 14.6% 3 or more signs and/or symptoms. The most frequent signs/symptoms were flat affect, autism/withdrawal (>40%), staring, and rigidity (>20%), whereas severe motor signs/symptoms such as stupor, mutism, catalepsy, and waxy flexibility were less frequent (5%-10%). The NCRS network revealed weak to moderate associations among affective, behavioral, and motor signs and symptoms. The BFCRS network demonstrated comparable interrelations, supporting the NCRS findings, whereas the network in the ICD-11 subgroup was unstable. CONCLUSIONS: Catatonia emerges as a dimensional syndrome with frequent subthreshold manifestations. While syndromal catatonia aligns with ICD-11 psychomotor domains, subthreshold presentations do not, highlighting the need for systematic screening and refined dimensional models beyond categorical diagnosis.