Amoxicillin and Clarithromycin Use and Delirious Mania in an Adolescent With Recurrent Catatonia and Psychosis

The intersection of pediatric psychiatry and infectious disease can present complex diagnostic challenges, particularly when symptoms of organic medical etiology mimic severe psychiatric disorders. This case study analyzes the clinical trajectory of an adolescent patient who developed delirious mania - a subtype of catatonia combining manic, delirious, and psychotic features - following the administration of clarithromycin and amoxicillin for Helicobacter pylori (H. pylori) gastritis. Initially presenting with psychosis and delirium attributed to a prior Coronavirus Disease 2019 (COVID-19) infection and recurrent cannabis use, the patient underwent six hospital admissions over four months. While the patient's initial symptoms were thought to be likely due to cannabis-induced psychosis, the emergence of treatment-resistant delirious mania during her sixth admission led to treatment shifts that resulted in symptom improvement. This case review proposes a methodological framework for mitigating "anchoring bias" and identifying iatrogenic or other triggers in treatment-refractory psychiatric presentations. Ultimately, this work emphasizes the critical need for continuous medical re-evaluation in psychiatric settings as well as demonstrates that even common antibiotic regimens, like "triple therapy" for H. pylori, can precipitate severe neuropsychiatric syndromes in vulnerable adolescents.