The Ontological Dissonance Hypothesis: AI-Triggered Delusional Ideation as Folie a Deux Technologique

This paper argues that contemporary large language models (LLMs) can contribute to psychotic involvement by creating interactions that resemble the relational dynamics of folie a deux. Drawing on Bateson's double bind theory, clinical literature on shared psychotic disorder, and McGilchrist's hemisphere theory, we show how the combination of high linguistic coherence and the absence of an underlying subject produces a structural tension for the user: language suggests an interlocutor, while intuition registers a void. In contexts of emotional need or instability, this tension can lead users to resolve the conflict through imaginative projection, attributing interiority, intention, or presence to a system that possesses none. The paper situates these dynamics within emerging clinical reports, develops a phenomenological account of how they unfold, and argues that current engagement-optimised design choices exacerbate the risk. We conclude by proposing 'ontological honesty' as a necessary design principle for mitigating technologically mediated folie a deux.