Developmental language disorder

Developmental language disorder (DLD) is identified when a child has problems with language development that continue into school age and beyond. The language problems have a significant impact on everyday social interactions or educational progress, and occur in the absence of autism spectrum disorder, intellectual disability or a known biomedical condition. The most obvious problems are difficulties in using words and sentences to express meanings, but for many children, understanding of language (receptive language) is also a challenge, although this may not be evident unless the child is given a formal assessment. Developmental language disorder (DLD) is identified when a child has problems with language development that continue into school age and beyond. The language problems have a significant impact on everyday social interactions or educational progress, and occur in the absence of autism spectrum disorder, intellectual disability or a known biomedical condition. The most obvious problems are difficulties in using words and sentences to express meanings, but for many children, understanding of language (receptive language) is also a challenge, although this may not be evident unless the child is given a formal assessment. The term developmental language disorder (DLD) was endorsed in a consensus study involving a panel of experts (CATALISE Consortium) in 2017. The study was conducted in response to concerns that a wide range of terminology was used in this area, with the consequence that there was poor communication, lack of public recognition, and in some cases children were denied access to services. Developmental language disorder is a subset of language disorder, which is itself a subset of the broader category of speech, language and communication needs (SLCN). The terminology for children’s language disorders has been extremely wide-ranging and confusing, with many labels that have overlapping but not necessarily identical meanings. In part this confusion reflected uncertainty about the boundaries of DLD, and the existence of different subtypes. Historically, the terms ‘’developmental dysphasia’’ or ‘’developmental aphasia’’ were used to describe children with the clinical picture of DLD. These terms have, however, largely been abandoned, as they suggest parallels with adult acquired aphasia. This is misleading, as DLD is not caused by brain damage. Although the term DLD has been used for many years, it has been less common than the term specific language impairment (SLI), which has been widely adopted, especially in North America. The definition of SLI overlaps with DLD, but was rejected by the CATALISE panel because it was seen as overly restrictive in implying that the child had relatively pure problems with language in the absence of any other impairments. Children with such selective problems are relatively rare, and there is no evidence that they respond differently to intervention, or have different causal factors, from other children with language problems. In the UK education system the term speech, language and communication needs (SLCN) is widely used, but this is far broader than DLD, and includes children with speech, language and social communication difficulties arising from a wide range of causes. The question of whether to refer to children's language problems as ‘disorder’ was a topic of debate among the CATALISE consortium, but the conclusion was that ‘disorder’ conveyed the serious nature and potential consequences of persistent language deficits. It is also parallel with other neurodevelopmental conditions and consistent with diagnostic frameworks such as DSM-5 and ICD-11. Where there are milder or more transient difficulties, language difficulties may be a more appropriate term. DLD can affect a range of areas of language and the degree of impairment in different areas of language can vary from child to child. However, although there have been attempts to define different subtypes, these have not generally resulted in robust categories. The recommendation of the CATALISE panel was that the specific areas of impairment should be assessed and documented for individual children, while recognizing that different children might have different combinations of problems. The areas which can be affected are: Speech is the act of articulating sounds, and this can be impaired for all kinds of reasons – a structural problem such as cleft lip and cleft palate, a neurological problem affecting motor control of the speech apparatus dysarthria, or inability to perceive distinctions between sounds because of hearing loss. Some distortions of speech sounds, such as a lisp, are commonly seen in young children. These misarticulations should not be confused with language problems, which involve the ability to select and combine linguistic elements to express meanings, and the ability to comprehend meanings. Although speech disorders can be distinguished from language disorders, they can also co-occur. When a child fails to produce distinctions between speech sounds for no obvious reason, this is typically regarded as a language problem affecting the learning of phonological contrasts. The classification of and terminology for disorders of speech sound production is a subject of considerable debate. In practice, even for those with specialist skills, it is not always easy to distinguish between phonological disorders and other types of speech production problem.Speech sound disorder (SSD) is any problem with speech production arising from any cause. Speech sound disorders of unknown cause that are not accompanied by other language problems are a relatively common reason for young children to be referred to speech-language therapy (speech-language pathology). These often resolve by around 4–5 years of age with specialist intervention, and so would not meet criteria for DLD. Where such problems continue beyond five years of age, they are usually accompanied by problems in broader language domains and have a poorer prognosis, so a diagnosis of DLD with SSD is then appropriate. DLD often co-occurs with milder neurodevelopmental disorders of unknown origin, such as attention-deficit hyperactivity disorder, developmental dyslexia or developmental co-ordination disorder. These do not preclude a diagnosis of DLD, but should be noted as co-occurring conditions.