Neurotransmitters in Auditory Processing Disorders and Neurodevelopmental Disorders: A Common Neurobiological...

Background/Objectives: Auditory processing disorders (APDs), defined as impaired neural processing of acoustic stimuli despite normal peripheral hearing, often co-occur with neurodevelopmental disorders (NDDs) and may contribute to language, attentional, and learning difficulties. Emerging evidence suggests that shared neurotransmitter systems may represent a common neurobiological substrate underlying these conditions. The aim of this study is to integrate current evidence on glutamatergic, GABAergic, and monoaminergic systems in neurodevelopmental and auditory processing disorders in children and adolescents, and to evaluate the hypothesis that shared neurotransmitter dysregulation may underlie their clinical overlap. Methods: A narrative review of the literature was conducted through electronic searches in PubMed and Embase up to 31 December 2025, using keywords related to neurotransmitters, NDDs and APDs. Results: Available evidence indicates that an imbalance between excitatory glutamatergic and inhibitory GABAergic neurotransmission has been proposed as a central mechanism in NDDs and may also contribute to auditory processing difficulties through altered neural synchrony, sensory gating and temporal auditory coding. Findings collectively suggest the hypothesis of shared neurotransmitter dysregulation across NDDs and APDs. Conclusions: Auditory processing difficulties may represent sensory-level expressions of shared neurochemical vulnerability across neurodevelopmental conditions. Future longitudinal and multimodal studies are needed to clarify causal relationships and to identify clinically useful biomarkers.