Developmental Language Disorder

What Causes Developmental Language Disorder?

Scientists don’t know what causes DLD; it is likely caused by a combination of genetic predisposition and external environmental factors.

Is Developmental Language Disorder Hereditary?

People with a family history of developmental language disorders have a higher risk of developing DLD themselves, suggesting a possible inherited component to the disorder. However, scientists have not yet identified a single gene definitively associated with DLD or other communication disorders. Sometimes a genetic predisposition may work in combination with environmental factors to trigger these disorders.

How Is Developmental Language Disorder Detected?

DLD typically begins in childhood as a child is learning how to speak. A certain degree of non-fluency is expected during this early development, making it challenging to spot the earliest signs of the disorder.

Some potential warning signs of DLD include:

• Late and/or slower than average language development
• Delays in using gestures to communicate
• Pronunciation that is atypical for a child of their age
• Speech that is difficult to understand
• Disorganized speech in conversation or while telling a story
• Problems with attention during conversation

How Is Developmental Language Disorder Diagnosed?

Diagnosis of DLD begins with determining that the child has a cluster of symptoms that meet the diagnostic criteria for the disorder. A doctor will start with a physical exam to rule out other problems that may be causing the symptoms. After these exams, if the doctor suspects that DLD is the cause of the symptoms, they may recommend consulting a speech pathologist to solidify the diagnosis.

Diagnostic steps may include:

• A physical exam. This exam will be aimed at ruling out physical conditions that could be causing the symptoms.
• Vision and hearing exams. These exams will rule out sensory causes for language development problems.
• Assessment by a speech-language pathologist. This assessment will attempt to understand the person’s ability to speak and understand language.

PLEASE CONSULT A PHYSICIAN FOR MORE INFORMATION.

How Is Developmental Language Disorder Treated?

Speech and language therapy is typically the most effective approach to improving DLD symptoms. Many children who get early treatment for DLD see improvement in their symptoms. However, DLD is typically a life-long condition and is likely to cause language difficulties into adulthood.

How Does Developmental Language Disorder Progress?

Some people with DLD will see improvement in their symptoms as they get older, but impairments often continue into adulthood. The effects of the disorder can sometimes cause serious mental health and social issues. Potential complications of DLD include:

• Low self-esteem
• Being bullied
• Problems with schoolwork
• Impairment of social relationships
• Anxiety or depression

How Is Developmental Language Disorder Prevented?

There is no known way to prevent DLD. However, recognizing the disorder early and intervening with treatment may lessen the severity of symptoms and help them resolve more quickly.

Developmental Language Disorder Caregiver Tips

DLD often exists alongside other mental health and brain-related conditions, a situation called co-morbidity. These disorders are commonly associated with DLD:

• DLD is sometimes associated with attention-deficit/hyperactivity disorder (ADHD).
• DLD often co-exists with learning disorders such as dyslexia.
• People with DLD are at increased risk of anxiety and depression.

Developmental Language Disorder Brain Science

Scientists have discovered differences in brain structure and activity between people with some language disorders and those who don’t have problems with language. Some of those differences include:

• One study found that children with language disorders had greater than typical brain volume in an area called the left inferior frontal cortex. This part of the brain plays an essential role in language comprehension and production.
• The study also found that children with language impairments had lower brain volume in the right caudate nucleus and the superior temporal cortex. The caudate nucleus is critical in learning, memory, and other cognitive functions. The superior temporal cortex is involved in associating sounds with memory, making it an important area for the comprehension of spoken language.

Developmental Language Disorder Research

Title: Maximizing Outcomes for Preschoolers With Developmental Language Disorders

Stage: Recruiting

Principal Investigator: Megan Y. Roberts, PhD

Northwestern University

Evanston, IL  

The objective of the proposed study is to evaluate the efficacy of the Enhanced Milieu Teaching-Sentence Focus (EMT-SF) intervention, implemented by caregivers and interventionists, relative to a control condition enrolling 108 30-month-old children and their caregivers. The central hypothesis is that intervention will improve overall child language skills at 49 months.

A multi-site, phase 2, randomized clinical trial will be used to determine whether communication support strategies are effective for improving language outcomes in children with emergent developmental language disorder.

At study entry, 108 children with emergent developmental language disorder (DLD) at 30 months of age will be randomly assigned 1:1 to either the EMT-SF treatment condition or a Business as Usual (BAU) control group. The control group is necessary to determine the efficacy of the EMT-SF intervention. The EMT-SF group is necessary to evaluate the effects of systematically teaching caregivers to use these strategies. Because all children in the study have language delays that will make them eligible to receive the early intervention services through the state early intervention program, children in both experimental conditions will receive state-provided community-based intervention according to their Individualized Family Service Plan – the current standard of care or from private speech language therapy providers. Children in the EMT-SF condition will receive an additional 18 months of interventionist plus caregiver-implemented intervention sessions. Children in both groups will be assessed at the start of the study and every three months until the child is 49 months old. The goal is to enroll all children at 30 months of age and provide a minimum of 60 of the planned 66 sessions of intervention to each child in the treatment condition; however, variability in age at study entry (e.g., 30 months), intervention dosage, and the number of assessment data points will be addressed in the statistical analysis.

Title: Retrieval-Based Word Learning in Developmental Language Disorder

Stage: Recruiting

Principal investigator: Laurence B. Leonard, PhD

Purdue University

West Lafayette, IN 

Children with developmental language disorder (DLD; also referred to as specific language impairment) experience a significant deficit in language ability that is longstanding and harmful to the children’s academic, social, and eventual economic wellbeing. Word learning is one of the principal weaknesses in these children. This project focuses on the word learning abilities of four- and five-year-old children with DLD. The goal of the project is to build on our previous work to determine whether, as we have found thus far, special benefits accrue when these children must frequently recall newly introduced words during learning. In this first in a series of studies, researchers will seek to increase the children’s absolute levels of learning while maintaining the advantage that repeated retrieval holds over comparison methods of learning.

Title: Neuroimaging Reveals Treatment-related Changes in DLD

Stage: Not Yet Recruiting

Principal investigator: Karla N Washington, PhD

University of Cincinnati

Cincinnati, OH

Children with developmental language disorders (DLD, aka specific language impairment), a prevalent pediatric disorder, experience hallmark grammar deficits with life-long impacts on educational and occupational outcomes. While effective and early interventions can mitigate the effects of DLD, not enough is known about the neural basis of DLD in young children, yet is needed to inform the design of more individualized interventions. This project uses neuroimaging and behavioral methods with the goal of better understanding the memory-language mechanisms that underlie grammar learning and impairment, while also considering their association to treatment-related changes in preschoolers with DLD.

Although the impact of developmental language disorder (DLD), a prevalent preschool disorder, can be mitigated through evidence-based and early interventions, little is known about the neural basis of DLD, especially in young children, yet it is useful in the design of efficacious treatments. While much of the evidence has been furnished by studies examining domain-specific processes (language network), domain-general processes relating to memory and language also offer valuable testing ground and present the opportunity to advance the current knowledge base. The Procedural circuit Deficit Hypothesis (PDH) posits that grammar deficits are explained by an impairment of procedural memory (rule learning, “knowing how”). This impairment is associated with structural abnormalities in connections between frontal brain regions and basal ganglia, with corresponding underactivation and reduced functional connectivity. However, the declarative memory system (semantic, “knowing what”), supported by cortical and subcortical regions in the temporal lobes, including the hippocampus, is spared, acting as a compensatory mechanism to offset grammar deficits.

This proposed research will use neuroimaging (functional MRI and diffusion imaging) to describe the neural basis (functional and structural connectivity) of grammar learning and treatment-related change using the PDH. The investigators will gather critical data regarding grammar learning in preschoolers with DLD before, after, and following a break in intervention (computer-assisted treatment: DLD treatment; “business as usual”: DLD no treatment) as part of a randomized controlled trial. The investigators will also include typically developing (TD) peers to inform development vs. disorder. The central hypothesis is a treatment designed to improve grammar learning will normalize the procedural learning network in association with increases in language function and that the degree of improvement may be associated with the underlying neurobiology of baseline grammar deficits.

Building on a robust history of recruitment and treatment of preschoolers with DLD, the investigators will enroll 184 preschoolers, 100 with DLD (n=50 treatment; n=50 no treatment controls), and 84 TD. Aim 1 will establish the relationship between functional and structural connectivity for preschoolers with DLD and their TD peers between regions in the procedural learning and declarative networks. In Aim 2, the investigators will establish the neurobiological basis of treatment-related changes in DLD only. The investigators examine potential changes in functional and structural connectivity between regions of the procedural learning and declarative memory networks and investigate whether treatment-related changes occur in the typical range (DLD and TD). To meet our scientific goals, the investigators pair behavioral tools (traditional grammar tools) with neuroimaging to describe co-occurring behavioral performance underlying learning and outcome. This research will contribute novel insights into mechanisms underlying learning and impairment to help advance the evidence-based management of DLD.