Enigma of autism regression mechanistic pathways, clinical phenotypes, and early intervention implications

Figure 1 Neurodevelopmental trajectories underlying autism regression. The schematic contrasts typical development with patterns of developmental plateau and regression in social-communication skills. Regression is characterized by a deviation from an expected developmental trajectory after a period of near-typical development, most commonly occurring between 12 months and 30 months of age. The shaded interval represents a critical developmental window characterized by rapid synaptic pruning and neural network reorganization, during which increasing social-cognitive demands may unmask underlying neurodevelopmental vulnerability. This framework highlights regression as a dynamic developmental process with implications for early identification and intervention.