Developmental Disabilities Research Reviews

Attention deficit hyperactivity disorder (ADHD) is a childhood-onset disorder that is considered one of the most common neurobehavioral disorders. The symptoms of ADHD should be cast, not as static or fixed neurobehavioral deficits, but rather in terms of underlying developmental processes. Targeting attentional disorders early in life can bring about fundamental alterations in the pathogenesis of ADHD, and thus prevent or moderate the course of the disorder. The developmental approach can enable predictions concerning characteristics of ADHD that develop over time and inform us about multiple risk and protective factors that transact to impact its development, as well as the development of a broad range of associated co-morbid features...

Early language delay (ELD) is a warning sign that may presage the presence of a later language impairment (LI). In order to allow more targeted identification and earlier intervention for LI, better diagnostic measures for toddlers are needed. Development of accurate predictive/diagnostic models requires consideration of a set of complex interrelated questions around definition, causality, and theories of LIs. A multifactorial model of language development and LI is essential to increase the accuracy of prediction...

The effective identification of neurodevelopmental disorders is essential for early diagnosis and provision of intervention services. For many of these conditions, one of the primary domains of abnormality is language development. This review addresses what is known about the earliest indicators of language impairment across a range of neurodevelopmental disorders; consideration is given to both behavioral and neural markers, as well as patterns of change over time. A summary of the current state of the field, including challenges in research, is presented...

Both small-scale and epidemiological longitudinal studies of early language delay indicate that most late talkers attain language scores in the average range by age 5, 6, or 7. However, late talker groups typically obtain significantly lower scores than groups with typical language histories on most language measures into adolescence. These findings support a dimensional account of language delay, whereby late talkers and typically developing peers differ quantitatively on a hypothetical language ability spectrum...

Advances in the identification of the early signs of autism spectrum disorder (ASD) have occurred despite the heterogeneity of the disorder and its variable onset and presentation. Using various methodologies including retrospective studies, community samples, and sibling cohorts, researchers have identified behavioral markers of the disorder that emerge over the first 2 years of life. However, there are characteristics of ASD that overlap with other types of developmental delay (DD), which may complicate differential diagnosis in young children...

Cerebral palsy (CP) is the most severe physical disability within the spectrum of developmental delay. CP is an umbrella term describing a group of motor disorders, accompanied by many associated impairments. The disability is a result of injuries to the developing brain occurring any time from the first trimester of pregnancy through to early childhood. However, for the great majority, their full etiological causal pathway remains unclear. It is important to discriminate as early as possible between: (a) mild or nonspecific motor delay, (b) developmental coordination disorder, (c) syndromes, (d) metabolic and progressive conditions, and (e) CP with its various motor types and distributions...

Preterm birth is characterized by multiple interacting atypical constraints affecting different aspects of neuropsychological development. In the first years of life, perceptual, motor, and communicative-linguistic abilities, as well as attention, processing speed, and memory are affected by preterm birth resulting in cascading effects on later development. From school age to adolescence, a catch-up of simpler competencies (i.e., receptive lexicon) along with a more selective effect on more complex competencies (i...

The challenge of identifying infants who are at risk for developmental delay and possible adverse neurodevelopmental outcome demands methods of evaluation that will lead to early intervention to minimize developmental disability and to maximize the infant's potential. A qualitative assessment of spontaneous general movements (GMs) in the preterm, term, and young infant at risk is a valid and reliable tool for evaluation (Prechtl [1990] Early Hum. Dev. 23:151-158). The aim of this review is to describe the theoretical and clinical bases for the assessment of GMs and its relationship to developmental delay and brain dysfunction...

Pediatricians play a leading role in the detection, diagnosis, and management of children with global developmental delay (GDD) and mental retardation (MR). Assessment, investigation, and consultation with the family are the prime responsibility of the developmental pediatrician, in collaboration with a multidisciplinary team. The model used by the developmental pediatrician depends on the community health framework. Significant progress has been recently achieved in identifying underlying etiologies, using a variety of laboratory tests including neuroimaging and genetic and metabolic investigations...

Neurobehavioral teratology refers to the study of the abnormal development of the structure and the behavioral functions of the central nervous system, which result from exposure to exogenous agents during prenatal development. The focus of this review is the effects of various prenatal exposures on human neurodevelopment. Studies that deal with the adverse effects of infectious agents (rubella, cytomegalovirus, and toxoplasma), teratogenic drugs (e.g., antiepileptic drugs such as phenytoin, valproate, and carbamazepine, coumarin derivatives, and retinoids), alcohol, and other substances of abuse will be reviewed...

A delay in meeting developmental milestones may be secondary to perinatal events, involving complicated interactions between mother and fetus during delivery. Maternal factors including weight, diet, and morbidities can affect neonatal adaptation and later development. Prematurity, low birth weight, and previous intrauterine insults as well as complications during delivery of a previously normal fetus increase the risk for perinatal stress. In this article, the literature on perinatal and early postnatal factors that underlie risks for developmental delay and disabilities is reviewed...

A significant percentage of children, ages 0-5 years, present with developmental delays. Delays can be global (GDD), when two or more developmental areas manifest at least 6 months delays, or specific (SDD)when it relates to a single functional area. This special issue reviews etiologies as well as clinical and research uses of the term, focusing on the potential for arriving at earlier specific diagnoses in cases of CP, ADHD, ASD and language impairments (LI).

People with intellectual disability (ID) have a long history of discrimination and stigmatization, and a more recent history of pride and self-advocacy. The early history suggests that people with ID are a vulnerable population and deserve special research protections as do some other groups; the disability rights movement of the late 20th century aligns people with ID more closely with the principle of autonomy that has guided clinical and research ethics for the last 40 years. In examining the history of people with ID and the prevailing framework of human subjects research protections in the United States, we conclude that people with ID do not require special protection in human subjects research...

This article explores social policy developments in the arena of intellectual and developmental disabilities. It begins by summarizing the challenges facing persons with intellectual disabilities and their caregivers in 1945. Families depended on a patchwork of over-crowded and under-funded large state institutions. Children with intellectual disabilities were marginalized from education and public services. Shame and stigma, along with the lack of community-based services, led many parents to institutionalize a child...

Public Law 99-457 extended the landmark Public Law 94-142 legislation to include early intervention for infants and toddlers with or at-risk for development of developmental disabilities. Currently over 300,000 infants and toddlers and their families in the United States receive services through Part C of the Individuals with Disabilities Education legislation. The law fostered interagency collaborations and included the child's parent or caregiver as an integral part of the intervention team. This article reviews the 26 years of legislation associated with educating young children with disabilities and the resulting early intervention service delivery system...

Individuals with intellectual disabilities experience health disparities and disparities in accessing health care services compared to individuals within the general population. In order to eliminate these disparities the contributors to them must be understood. In this article, we aim to describe a recent reconceptualization of health and disability (Krahn, et al. [2006] Mental. Retard. Dev. Disabilities Res. Rev. 12:70-82) to further understand the health disparities between individuals with Down syndrome, the most common identified cause of intellectual disability in the United States, and the general population...

Down syndrome is the most common cause of intellectual disability. In the United States, it is recommended that prenatal testing for Down syndrome be offered to all women. Because of this policy and consequent public perception, having Down syndrome has become a disadvantage in the prenatal period. However, in the postnatal period, there may be some advantage in having Down syndrome. To help parents make informed decisions about screening and testing, it is crucial to reconcile divergent prenatal and postnatal perspectives...

Faced with the limitations of currently available mainstream medical treatments and interventions, parents of children with neurodevelopmental disorders often seek information about unproven interventions. These interventions frequently have undetermined efficacy and uncertain safety profiles. In this article, we present a general background and case vignettes that highlight the use of hyperbaric oxygen chambers and stem cells in cerebral palsy, the leading cause of pediatric physical disability. We then review the current evidence about these interventions as exemplars of unproven therapies...

Public policy surrounding newborn screening is in flux. New technology allows more screening for more diseases at lower cost. Traditional criteria for target diseases have been criticized by leading health policymakers. The example of newborn screening for Krabbe disease highlights many of the dilemmas associated with population-based screening programs. Krabbe is difficult to diagnose, variable in its natural history, and does not always respond to treatment. The only available treatment is hematopoietic stem cell transplantation, which is expensive, risky, and of uncertain efficacy...

Newborn screening (NBS), since its implementation in the 1960s, has traditionally been successful in reducing mortality and disability in children with a range of different conditions. Lysosomal storage disorders (LSD) are a heterogeneous group of inherited metabolic diseases that result from lysosomal dysfunction. Based on available treatment and suitable screening methods, the LSDs that are considered for NBS generally include Fabry, Gaucher, Krabbe, MPSI, MPSII, MPSV, Metachromatic leukodystrophy, Niemann-Pick, and Pompe...