When Delusion Becomes Reality: A Six‐Year Diagnostic Odyssey and Ethical Crisis in a Case of Veridical Spousal Infidelity Belief

Background The diagnosis of delusional disorder, jealousy type, traditionally relies on the criterion of a “false” belief. This report describes a complex case in which a belief long considered delusional was ultimately verified, revealing limitations of rigid diagnostic frameworks and raising a profound ethical dilemma. Case Presentation Ms. A, a 42‐year‐old woman, presented with a fixed, 4‐year belief in her husband’s infidelity, accompanied by mild depressive symptoms but preserved global functioning. Over a 6‐year period, she received treatment from multiple psychiatrists, including sequential trials of antipsychotics (risperidone, olanzapine, and aripiprazole) without benefit. Documented treatment resistance led to a trial of electroconvulsive therapy (ECT). Following the first ECT session, her husband confessed to long‐term infidelity and a secret remarriage, while demanding that the clinician withhold this information from the patient. Discussion This case challenges the diagnostic emphasis on belief falsity and illustrates how prolonged familial deception can sustain misdiagnosis. The protracted, multiprovider treatment history likely contributed to diagnostic entrenchment and therapeutic escalation. Ethically, maintaining secrecy after the confession constituted institutional gaslighting and epistemic injustice, violating core principles of nonmaleficence and autonomy. The clinician’s primary duty to the patient must supersede spousal demands for confidentiality in cases of harmful deception. Conclusion Veridical “delusions” require a paradigm shift toward dynamic diagnosis and patient‐centered ethics. Clinicians must critically evaluate collateral information, remain alert to epistemic injustice, and prioritize patient welfare and truth disclosure over preservation of harmful familial secrets.