From altered familiarity to delusional misidentification: the development of Capgras Syndrome in functional psychoses.

Background Capgras syndrome has traditionally been conceptualized either as a disorder of belief evaluation or as the consequence of disrupted affective familiarity. In functional psychoses, however, the impostor delusion may represent the endpoint of a progressive transformation of interpersonal experience rather than a sudden delusional event. A phenomenological account of the experiential trajectory preceding its crystallization remains largely undeveloped. Summary We propose a phenomenologically informed heuristic staging model describing the transition from altered familiarity to Capgras delusion. The earliest phase involves loss of affective familiarity despite preserved perceptual recognition of a significant other. This discrepancy progressively acquires an uncanny quality, followed by perplexity and an escalating search for explanatory meaning. Delusional crystallization occurs when the contradiction between perceptual sameness and affective unfamiliarity is resolved through the impostor hypothesis. Integrating phenomenological psychopathology with cognitive neuropsychiatric models, the proposed sequence conceptualizes Capgras delusion as a process of meaning reconstruction emerging from a prior alteration of lived interpersonal experience. Key points Uncanniness, perplexity, and meaning reconstruction are not specific to Capgras and may characterize delusion formation more broadly. We propose that Capgras specificity lies instead in their organization around a distinctive experiential configuration: preserved recognition combined with progressive erosion of affective familiarity, ultimately resolved through impostor attribution. Although heuristic rather than empirically validated, this model generates testable predictions regarding the temporal emergence of altered familiarity, interpersonal perplexity, and delusional misidentification, and may provide a framework for prospective investigation in early psychosis.