Neurotrophins in Neurodevelopmental Disorders: A Narrative Review of the Literature.

Neurodevelopmental disorders (NDDs), including attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), intellectual disability (ID), and tic disorders, comprise a range of conditions that originate in early childhood and impact cognitive, behavioral, and social functioning. Despite their clinical heterogeneity, they often share common molecular and neurobiological framework. This narrative review aims to examine the role of neurotrophins-particularly the brain-derived neurotrophic factor, nerve growth factor, and related molecules-in the pathophysiology of NDDs, and to explore their potential as biomarkers and therapeutic targets. A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science, including both clinical and preclinical studies. Neurotrophins are critically involved in brain development, influencing neurogenesis, synaptic plasticity, and neuronal survival. Dysregulation in their signaling pathways has been associated with core features of ASD and ADHD and may modulate cognitive outcomes in ID. Emerging evidence also supports a role for neuroimmune interactions and neurotrophic dysfunction in tic disorders. However, findings across studies remain inconsistent due to methodological variability and limited longitudinal data. Future research should aim for standardized methodologies and stratified, longitudinal designs to clarify their role across developmental stages and clinical phenotypes.