Cancer and folie à deux: case report, treatment, and implications.

PURPOSE: This report describes the uncommon psychopathological state best known as folie à deux, or shared psychotic disorder, in a unique case in which the grandiose, religious delusions of a woman with uterine cancer are shared with her husband. OVERVIEW: More than 50% of patients with cancer meet the criteria for diagnosis of major psychiatric disorders. Certainly, these disorders may occur as a result of the stress of the cancer diagnosis and treatment, but also because of a predisposition to psychiatric illness or a pre-existing psychiatric illness. In the medical setting, the phenomenon of folie à deux poses significant problems not only for the patient, but also for the involved family member, psychiatric consultant, and healthcare team. CLINICAL IMPLICATIONS: In this case, the patient's delusional system had a grave impact on her ability to make rational healthcare decisions, for which she was deemed incompetent. The first choice for her healthcare surrogate, her husband, was so affected by his sharing of her psychotic condition that he could not fulfill this role. In assessing a suspected case of folie à deux, awareness of several issues--the point at which religious over-ideation becomes delusional, the spectrum of competency, informed consent, and treatment refusal--is important.