Beyond diagnostic categories: sensory processing as a transdiagnostic mechanism in autism, ADHD, and PTSD - a...

The post-pandemic surge in adult ADHD presentations has intensified a question that categorical diagnosis tends to foreclose: What do autism, ADHD, and PTSD share at the level of developmental organization? This paper offers a conceptual analysis of sensory processing differences as a transdiagnostic mechanism linking these three conditions, examined through a neuropsychoanalytic lens. Drawing on current empirical literature and the French psychosomatic tradition, we explore how the sensory modalities most consistently implicated across all three (auditory, tactile, and vestibular) are precisely those that achieve functional maturity in utero, rendering their organization vulnerable to the quality of the prenatal sensory environment. Maternal prenatal stress, mediated through HPA axis activation and epigenetic programming of the NR3C1 glucocorticoid receptor gene, constitutes one documented pathway through which this vulnerability may be established. We further examine how Bydlowski's concept of psychic transparency during pregnancy, in which the usual defenses against unconscious material are lowered and archaic, unprocessed material resurfaces, may provide a psychoanalytic account of intergenerational beta element transmission, whose somatic correlate is the molecular inscription documented by prenatal stress research. The self-soothing and self-regulatory behaviors observed across these three populations are reconsidered not as symptoms to be eliminated but as proto-alpha mechanisms: bodily attempts at psychic organization where adequate containment has been unavailable. Clinical and research implications of this conceptual framework are discussed.