Catatonia can be associated with a diverse range of conditions, including autoimmune encephalitis. Although rare, autoimmune encephalitis accounts for a significant proportion of catatonia cases with autoimmune aetiologies. In instances where autoimmune mechanisms are suspected, autoantibody testing is a key component of the diagnostic evaluation. However, test results should always be interpreted in conjunction with clinical findings. This article highlights the diagnostic challenges involved, advocating for structured diagnostic algorithms and timely initiation of immune therapy in carefully selected cases – particularly when antibody confirmation is absent. It revisits the paper, ‘Retrospective chart review of cases with steroid-responsive catatonia: exploring a potential autoimmune etiology’.