Terminology The term<unk>  <unk>  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.<unk>  is a subset of<unk><unk> , which is itself a subset of the broader category of speech,<unk>  and communication needs (SLCN). The terminology for children’s<unk><unk> s 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<unk> , and the existence of different subtypes. Historically, the terms ‘’developmental dysphasia’’ or ‘’developmental aphasia’’ were used to describe children with the clinical picture of<unk> . These terms have, however, largely been abandoned, as they suggest parallels with adult acquired aphasia. This is misleading, as<unk>  is not caused by brain damage. Although the term<unk>  has been used for many years, it has been less common than the term specific<unk>  impairment (SLI), which has been widely adopted, especially in North America. The definition of SLI overlaps with<unk> , but was rejected by the CATALISE panel because it was seen as overly restrictive in implying that the child had relatively pure problems with<unk>  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<unk>  problems. In the UK education system the term speech,<unk>  and communication needs (SLCN) is widely used, but this is far broader than<unk> , and includes children with speech,<unk>  and social communication difficulties arising from a wide range of causes. The question of whether to refer to children's<unk>  problems as<unk> ’ was a topic of debate among the CATALISE consortium, but the conclusion was that<unk> ’ conveyed the serious nature and potential consequences of persistent<unk>  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,<unk>  difficulties may be a more appropriate term. Areas of<unk>  difficulty<unk>  can affect a range of areas of<unk>  and the degree of impairment in different areas of<unk>  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: * Grammar – This involves the ability to combine words into grammatically correct sentences (syntax) and to combine parts of words together (morphology) such as adding grammatical endings to verbs like -ing or -ed or to add prefixes and suffixes like dis- or -ation. For instance, a child may say 'me jump here', instead of 'I jumped here'. Comprehension of sentences can also be affected. For instance, there may be difficulty understanding meaning expressed by word order, and so confusion about what is blue in a sentence like 'the pencil on the shoe is blue', and a tendency to use general knowledge rather than linguistic cues to meaning, or problems in interpreting grammatical markers of number or tense. * Semantics – This refers to children’s ability to understand the meaning of words and how meanings are expressed by combining words together. Children with<unk>  often have limited vocabulary and may make heavy use of a small set of words with rather general meanings. As children with<unk>  get older, they may have a hard time understanding that some words have multiple meanings, for example the word “cold,” which can mean a low temperature, a sickness, or being unfriendly. * Word finding – Children with word finding difficulties may know a word, but have difficulty accessing it for production – similar to the tip of the tongue phenomenon. * Pragmatics – Pragmatics refers to the ability to select the appropriate message, or interpret what others say, in relation to context. Pragmatic difficulties can give an impression of oddity, with the content of<unk>  not fitting the environmental or social context; comprehension may be over-literal; the child may chatter incessantly, be poor at turn-taking in conversation and maintaining a topic * Discourse – Discourse refers to a level of organization of<unk>  beyond the sentence. Child with limitations in this domain may have limited ability to tell a story or describe a set of events in a logical sequence * Verbal memory and learning – Problems with remembering words or sentences can affect both the learning of new vocabulary, and the understanding of long or complex sentences. Young children with<unk>  may say their first words later than other children. It may also take children with<unk>  longer to learn and remember novel words. * Phonology – Phonology is the branch of linguistics concerned with the way sounds are combined together in words. Children with difficulties with phonology may fail to distinguish between certain speech sounds, such as 't' and 'k', so that 'cake' is produced as 'tate'. Such difficulties are not unusual as part of typical development in toddlers, but they would usually resolve by the time children are 4–5 years old. Difficulties with producing some speech sounds accurately may reduce intelligibility of speech. In addition, more subtle difficulties in recognising specific sounds in words (phonological awareness) can lead to literacy difficulties. Relationship with speech<unk> s 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<unk>  problems, which involve the ability to select and combine linguistic elements to express meanings, and the ability to comprehend meanings. Although speech<unk> s can be distinguished from<unk><unk> s, 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<unk>  problem affecting the learning of phonological contrasts. The classification of and terminology for<unk> s 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<unk> s and other types of speech production problem. Speech sound<unk>  (SSD) is any problem with speech production arising from any cause. Speech sound<unk> s of unknown cause that are not accompanied by other<unk>  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<unk> . Where such problems continue beyond five years of age, they are usually accompanied by problems in broader<unk>  domains and have a poorer prognosis, so a diagnosis of<unk>  with SSD is then appropriate.<unk>  impairment compared to other common<unk>  related<unk> s Relationship with other neurodevelopmental<unk> s<unk>  often co-occurs with milder neurodevelopmental<unk> s of unknown origin, such as attention-deficit hyperactivity<unk> , developmental dyslexia or developmental coordination<unk> . These do not preclude a diagnosis of<unk> , but should be noted as co-occurring conditions.
Developmental language disorder
Expressive language disorder
Developmental disability
Pervasive developmental disorder
Multiple complex developmental disorder
Nonverbal autism
Low-functioning autism
Mixed receptive-expressive language disorder