Catatonic Features That May Be Mistaken for Worsening Autism Show Treatment-Associated Improvement: Implications for...

Catatonia in autistic individuals may resemble worsening autism yet represent a potentially treatable departure from baseline functioning. We compared item-level catatonic signs in autistic and non-autistic patients and evaluated treatment-associated change during electroconvulsive therapy (ECT). This single-center observational cohort included patients with catatonia who received ECT from May 2022 through April 2026. The 23-item Bush-Francis Catatonia Rating Scale (BFCRS) was assessed longitudinally. Pretreatment BFCRS data were available for 104 patients, including 41 autistic and 63 non-autistic patients, with 993 near-complete repeated assessments available. Pretreatment item presence was modeled using a three-level clinical-group variable with adjustment for age, biologic sex, and calendar year. Compared with non-autistic patients, patients with autism and intellectual disability had higher adjusted odds of eight activated, repetitive, or behaviorally dysregulated signs and lower odds of immobility/stupor. Among 96 patients with paired first and last eligible BFCRS assessments, multiple items improved in both cohorts. Generalized estimating equations demonstrated longitudinal declines in total BFCRS scores and multiple psychomotor-domain scores, with no clinical-group-by-time interaction surviving false-discovery rate correction in unrestricted or 30-, 60-, 90-, and 180-day models. Autism-specific Kanner analyses identified significant fixed-endpoint improvement in seven severity items after false-discovery rate correction, six of which were reproduced longitudinally. Catatonia in autistic patients with intellectual disability was characterized by a phenotype that may resemble worsening autism during later regression, and many constituent signs demonstrated treatment-associated improvement during ECT.

Some autistic individuals experience later behavioral, motor, or functional regression, which may have potentially treatable causes such as catatonia. In this study, patients with autism and intellectual disability were more likely to show activated, repetitive, and behaviorally dysregulated catatonic features than non-autistic patients, and these features improved during treatment. Catatonia should be considered when an autistic person develops new or substantially worsening repetitive behavior, impulsivity, aggression, communication loss, reduced self-care, mobility changes, food refusal, or other departures from prior functioning.