Introduction to Neurodevelopmental Disorders

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Ann Child Neurol. 2026;34(1):1-4

Publication date (electronic) : 2026 January 1

doi : https://doi.org/10.26815/acn.2025.01354

Baik-Lin Eun, PhD^,1, Hee Jung Chung, PhD²

¹Department of Pediatrics, Korea University College of Medicine, Seoul, Korea

²Department of Pediatrics, CHA Gangnam Medical Center, CHA University, Seoul, Korea

Corresponding author: Baik-Lin Eun, PhD Department of Pediatrics, Korea University Guro Hospital, Korea University College of Medicine, 148 Gurodong-ro, Guro-gu, Seoul 08308, Korea Tel: +82-2-2626-1229 E-mail: bleun@korea.ac.kr

Received 2025 December 22; Accepted 2025 December 22.

Abstract

Introduction

Neurodevelopmental disorders (NDDs) represent a major cause of lifelong disability and account for a substantial proportion of referrals in pediatric neurology and developmental pediatrics [1,2]. According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), NDDs are defined as disorders with onset during the developmental period that result in impairments in personal, social, academic, or occupational functioning [1]. The deficits associated with these disorders range widely, from highly specific limitations in learning or communication to global impairments in social interaction or intellectual function. Although traditionally classified as discrete diagnostic entities, NDDs are increasingly recognized as conditions that affect multiple interconnected developmental domains, including cognition, language, motor function, social interaction, and adaptive behavior [3]. The burden of NDDs is substantial, affecting not only children with these conditions but also their families, educational systems, and healthcare resources. Over recent decades, remarkable progress has been made in understanding the neurobiological basis of NDDs, driven largely by advances in neuroimaging, molecular genetics, and large-scale epidemiological studies.

In particular, advances in molecular genetics, including next-generation sequencing (NGS) technologies, have transformed diagnostic strategies for children with NDDs [4,5]. In parallel, emerging digital health technologies are expanding therapeutic paradigms beyond conventional, therapist-centered models [6,7].

This review provides an integrated overview of NDDs, encompassing clinical classification, diagnostic strategies, and emerging therapeutic innovations.

Classification and Core Domains of Neurodevelopmental Disorders

NDDs encompass a broad spectrum of conditions, including intellectual disability (ID), communication disorders, autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder, specific learning disorders, and motor disorders (Table 1) [1]. These conditions share impairments across core developmental domains, including motor development (gross and fine motor skills), speech and language development (expressive and receptive language), social and emotional development, and cognitive development (Fig. 1) [8,9]. The acquisition of developmental skills reflects the complex interplay among maturation of the nervous system, the functioning of other organ systems, and the child’s social and physical environment, including exposure to appropriate stimuli [10]. Despite diagnostic distinctions, impairments frequently overlap across multiple developmental domains, as summarized in Table 2 [11]. Accordingly, a domain-based approach is essential, given the frequent overlap of deficits and the evolution of clinical presentations over time, particularly in young children whose features change with development. For example, early motor or language delays may precede later diagnoses of ASD or ID, underscoring the importance of longitudinal surveillance and repeated developmental assessments [3]. This domain-based perspective also explains the high prevalence of comorbidities and the dynamic nature of diagnostic trajectories in early childhood [3].

Table 1.

Diagnostic and Statistical Manual of Mental Disorders classification of neurodevelopmental disorders

Fig. 1.

Core domains of neurodevelopment and their overlap.

Table 2.

Types of neurodevelopmental disorders and abnormalities by domains

Etiological Diagnosis in Neurodevelopmental Disorders

Etiological diagnosis plays a critical role in informing prognosis, guiding targeted interventions, enabling genetic counseling, and, in some cases, identifying treatable conditions [3]. Historically, the diagnostic yield for identifying an underlying cause of NDDs was limited. However, the introduction of chromosomal microarray analysis and NGS has substantially increased detection rates [4,5].

The evolution from Sanger sequencing to NGS has revolutionized the field of etiological diagnosis. The completion of the Human Genome Project marked a major turning point, reducing sequencing time from years to days and lowering costs to under $1,000 per genome. These advances have facilitated the widespread clinical adoption of chromosomal microarray analysis, targeted gene panels, whole-exome sequencing (WES), and whole-genome sequencing (WGS). Current evidence indicates that WES and WGS provide superior diagnostic yield compared with traditional testing approaches, particularly in children with unexplained developmental delay, ID, epilepsy, or syndromic features [4]. Collectively, these findings support early and comprehensive genetic evaluation as an integral component of standard diagnostic workups for NDDs.

Early Identification and Developmental Surveillance/Screening

Early identification of developmental delays remains a cornerstone of effective intervention in NDDs [6]. Developmental surveillance and standardized screening programs enable the detection of atypical developmental trajectories before overt clinical diagnoses become apparent. In Korea, the National Health Screening Program for Infants and Children has been implemented nationwide since November 2007 to monitor the growth and development of infants and children and to provide age-appropriate health education to caregivers through structured health check-up programs. This program incorporates developmental screening using the Korean Developmental Screening Test for Infants and Children (K-DST), thereby facilitating early identification of children with developmental concerns and timely referral to appropriate medical institutions [12]. Importantly, delays in diagnosis are associated with missed opportunities for early intervention, which has been shown to improve cognitive, language, and adaptive outcomes. A domain-based approach supports early referral and intervention even when diagnostic certainty is limited, reflecting the overlapping and dynamic nature of neurodevelopment (Fig. 1) [3,6].

Therapeutic Approaches and Digital Therapeutics

Management of NDDs has traditionally relied on multidisciplinary interventions, including behavioral therapy, speech and language therapy, physical and occupational therapy, and educational support [1,6]. Although these approaches are effective, they are resource-intensive and may be constrained by limitations in accessibility, scalability, and long-term adherence. Digital therapeutics have emerged as evidence-based, software-driven interventions designed to complement conventional therapies. These interventions deliver therapeutic content through digital platforms such as tablets and smartphones, offering scalable, personalized, and data-driven treatment options. Such tools enable continuous monitoring and adaptive intervention tailored to individual needs [7,13]. Recent studies indicate that digital therapeutics can improve cognitive and executive functioning, attention, and adaptive skills in children with NDDs, particularly when implemented in conjunction with conventional therapeutic modalities.

Conclusion

NDDs are complex and heterogeneous conditions that require integrated diagnostic and therapeutic strategies. Advances in genetic diagnostics have transformed etiological evaluation, while digital therapeutics are expanding the therapeutic landscape. The convergence of genomics, neurodevelopmental science, and digital health heralds a shift toward precision medicine in the care of children with NDDs. By integrating genetic etiology, detailed phenotypic profiling, and real-world behavioral data, clinicians can increasingly tailor interventions to individual developmental trajectories. Continued integration of these innovations into routine clinical practice will be essential for improving long-term outcomes in children with NDDs.

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