An increasing amount of attention is being paid to dyslexia and autism. These neurodevelopmental disorders affect a large number of children, to the point where they have become household names for many families, caregivers and educators. However, there is another disorder that is just as common – if not more so – but it remains largely unknown: developmental language disorder (DLD).
DLD is a neurodevelopmental disorder that hinders language learning and use, without any obvious cause such as hearing loss, intellectual disability or autism. It can affect comprehension or expression, either independently or simultaneously.
It is estimated that this disorder affects between 7% and 10% of school-age children. However, it often goes unnoticed, or it is mistaken for immaturity, laziness or behavioural problems.
DLD is not a simple delay that resolves itself over time. It is persistent, and if left untreated it can have a serious impact on school performance, social relationships and self-esteem.
An invisible disorder
DLD is considered an invisible condition, in that there are no physical traits that give it away. Many children with DLD manage well in everyday conversations, but get stuck when language becomes more complex, such as when reading a textbook, listening to a scientific explanation, or understanding a joke.
Read more:
Children born or raised during lockdown are developing language skills at a slower rate
On a day-to-day basis, parents may notice that their child does not understand long sentences (“put the glass on the table and then bring me the spoon”). They may also use very short sentences, omit certain words (“boy play car” instead of “the boy plays with the car”), or have trouble recounting what they did on the playground or in class.
Historically, DLD has been given different names – “specific language impairment” or SLI, and “mixed receptive-expressive disorder” – which has caused confusion and limited its visibility. The international CATALISE project has advocated for the use of the term of DLD, and for clearer criteria for identifying it.
Warning signs at different ages
Every child with DLD has a different profile, but there are some common warning signs to look out for:
-
At preschool age: difficulty following instructions, very short sentences, problems learning songs or recounting what happened during the day.
-
At school age: difficulties understanding texts, using complex sentences, learning new vocabulary, frequent grammatical and spelling errors, or problems writing coherently.
Distinguishing DLD from other disorders
DLD can be confused with other well-known neurodevelopmental disorders. However, it has several clear distinguishing features:
-
It is not dyslexia. Dyslexia causes difficulties in learning to read and write, especially in decoding words and phonological skills. For example, a child with dyslexia may confuse visually similar letters (such as b and d, or p and q) or read the word “house” as “mouse”, even though they have a rich oral vocabulary and well-structured spoken sentences.
In contrast, a child with DLD may read “house” correctly but not understand the meaning of the whole sentence. They may also have more limited oral language skills, and make grammatical errors when speaking.
-
It is not autism. With DLD, social skills and communicative intent are usually preserved, even if language is limited. Although in early years both conditions may manifest as children being “late talkers”, studies show that children with DLD tend to use gestures, respond better to language, and play symbolically, while autism is characterised by greater problems with comprehension and social contact, as well as repetitive behaviours.
- It does not depend on non-verbal IQ. In the past, DLD was only diagnosed if a child’s nonverbal intelligence was within the average range, as a way to distinguish it from general learning disability. Today we know that some children with DLD score slightly lower on these tests, but that does not mean they have an overall impairment. For this reason, specialists no longer use the discrepancy between verbal and non-verbal ability as part of diagnostic criteria.
Long-term impacts
DLD does not disappear with age. Although many children improve with intervention, difficulties often accompany them into adolescence and adulthood. Longitudinal studies show that young people with DLD are more likely to have reading and writing problems (ranging from mild to persistent), drop out of school earlier, encounter more barriers to employment, and suffer from self-esteem and mental health issues.
This does not mean that the prognosis is necessarily negative. With early diagnosis and specialised support, many manage to function successfully at school and in daily life.
Interventions and treatments for DLD focus on strengthening both oral and written language: working on vocabulary, grammar and storytelling with a speech therapist, using visual aids and curricular adaptations at school, and encouraging shared reading and conversations at home.
At school, teachers can help by giving clear and concise instructions, and make sure that the child has understood them. They can also use diagrams or supporting images, and offer extra time for exams and assignments.
At home, parents can read with their children every day, expand on what the child says by modelling correct sentences (if they say “water here”, correct them to “yes, the water is here on the table”), and encourage them to tell stories about their day.
The importance of early intervention
Early support is essential because language is the foundation of reading, writing and school learning. The sooner a child receives help, the easier it will be to reduce future difficulties – a child who receives help at 4–5 years of age can make significantly better progress than one who receives it at 9–10, when they are already experiencing academic failure and frustration.
Diagnosing DLD requires professional assessment, usually carried out by speech therapists or language specialists. However, parents and teachers are always the first to suspect something is wrong. If a child is not progressing in language like their peers, if their sentences are very short, if they avoid participating in conversations or become frustrated with reading, it is best to seek advice. Early action is essential.
DLD is common, persistent and yet one of the least known neurodevelopmental disorders. Recognising its signs and distinguishing it from other problems is essential for timely intervention. As the experts from the CATALISE project point out, language is the foundation of learning, and supporting these children from an early age is the best way to open up opportunities for them in the future.
