Folie à Deux in the Family Environment: A Case of Shared Delusion Between a Mother and Her Son.

Shared psychotic disorder (SPD), also called folie à deux, is an uncommon clinical entity characterized by the transmission of delusions from one psychotic individual to another within the framework of a close relationship, typically isolated from the social environment. Although rare, this phenomenon poses a significant diagnostic and therapeutic challenge, particularly in family settings. This report presents a clinical case of folie à deux between a mother and her child, highlighting the complexities of therapeutic management and providing a succinct review of the literature to adequately frame the clinical approach. The report illustrates the need for a comprehensive therapeutic intervention involving both the management of the underlying psychotic disorder and the dissolution of pathological family dynamics that perpetuate shared delusions. Additionally, the importance of a multidisciplinary approach is emphasized, as shared delusions can involve multiple members of a nuclear family, increasing the risk of negative consequences at both individual and social levels.