Developmental language disorder

Essential (Required) Features:

• Persistent deficits in the acquisition, understanding, production or use of language (spoken or signed). Any of the following specific components of language skill may be differentially impaired, with relative weaknesses in some and relative strengths in others, or impairment may be more consistent across the different component skills.
• The ability to decompose words into constituent sounds and mentally manipulate those sounds (i.e., phonological awareness).
• The ability to use language rules, for example regarding word endings and how words are combined to form sentences (i.e., syntax, morphology, or grammar).
• The ability to learn, understand, and use language to convey the meaning of words and sentences (i.e., semantics).
• The ability to tell a story or have a conversation (i.e., narrative or conversational discourse).
• The ability to understand and use language in social contexts, for example making inferences, understanding verbal humour and resolving ambiguous meaning (i.e., pragmatics).
• Language abilities are markedly below what would be expected for age.
• The onset of language difficulties occurs during the developmental period, typically during early childhood.
• Language deficits result in significant limitations in communication, with functional impact in daily life at home, school, or work.
• The language deficits are not better accounted for by a Disorder of Intellectual Development, Autism Spectrum Disorder, another Neurodevelopmental Disorder, a sensory impairment, or a Disease of the Nervous System, including the effects of brain injury or infection (e.g., due to trauma, stroke, epilepsy, or meningitis).

Additional Clinical Features:

• In typical development, understanding and production of the different components of language are tightly correlated and develop in tandem. In Developmental Language Disorder, this developmental relationship may be out of step, with differential impairment in any of the component language skills.
• Many children with Developmental Language Disorder exhibit a discrepancy between verbal and nonverbal ability, but this is not a requirement for diagnosis.
• Developmental Language Disorder frequently co-occurs with other Neurodevelopmental Disorders, such as Developmental Speech Sound Disorder, Developmental Learning Disorder, Attention Deficit Hyperactivity Disorder, Autism Spectrum Disorder and Developmental Motor Coordination Disorder.
• Developmental Language Disorder is often associated with difficulties in peer relationships, emotional disturbance and disruptive behaviours, particularly in school-age children.
• Developmental Language Disorder often runs in families.
• Developmental Language Disorder can be a presenting feature in some individuals with specific chromosomal anomalies, including sex chromosome anomalies. Where available, chromosome testing can assist in identifying other health risks associated with specific underlying chromosomal abnormalities. If a specific chromosomal or other developmental anomaly is identified, this should be diagnosed in addition to the Developmental Language Disorder.
• Regression of language skills once acquired is not a feature of Developmental Language Disorder. Reported loss of early first words in the second year of life associated with a decline in social and communication behaviours —and, more rarely, loss of language skills after 3 years of age—may be a presentation of Autism Spectrum Disorder. Language abilities may also be lost due to Diseases of the Nervous System including acquired brain injury from stroke, trauma, or encephalopathy with or without overt epilepsy. Concomitant loss of physical skills with language abilities may be indicative of a neurodegenerative condition. When an underlying neurological cause has been identified, the condition should not be diagnosed as Developmental Language Disorder but rather as Secondary Speech or Language Syndrome, which should be assigned in addition to the appropriate diagnosis for the underlying condition.

Boundary with Normality (Threshold):

• Children vary widely in the age at which they first acquire spoken language and in the pace at which language skills become firmly established. The majority of pre-school children who acquire speech later than expected go on to develop normal language abilities. Very early delays in language acquisition are therefore not indicative of Developmental Language Disorder. However, the absence of single words (or word approximations) by the age of 2 years, the failure to generate simple two-word phrases by 3 years of age, and language impairments that are persistent over time are more likely to indicate Developmental Language Disorder, especially in the context of a known family history of language or literacy learning problems. By age 4 years, individual differences in language ability are more stable.
• Pronunciation and language use may vary widely depending on the social, cultural, and other environmental context (e.g., regional dialects). However, within any typical cultural setting, a Developmental Language Disorders is characterized by significant deficits in language abilities relative to the person’s same-aged peers in the community. A bilingual environment is not a cause of persistent language learning impairment.

Course Features:

• The course of Developmental Language Disorder may vary with the type and severity of symptom profile: impairment of receptive and expressive language (as compared to those with impairment of mainly expressive language) is more likely to be persistent and is associated with subsequent difficulties in reading comprehension.
• The particular pattern of language strengths and deficits may change over the course of development.
• Unlike Developmental Speech Sound and Speech Fluency disorders, Developmental Language Disorder is more likely to be maintained throughout development and into adulthood: approximately 75% of individuals diagnosed with Developmental Language Disorder in childhood continue to meet the diagnostic requirements for the disorder in late adolescence. The impact of these impairments continues to be evident into early adulthood as behavioural, social, adaptive, and communication problems, often with life-long social consequences.

Developmental Presentations:

• Developmental Language Disorder emerges early in development, though it can be challenging to distinguish typical variations from impairments in language development prior to age four. Diagnosis from age four onwards tends to yield a more stable symptom presentation and is more likely to be persistent.
• The prevalence of Developmental Language Disorder among children is estimated at 6 – 15%, but is more common among children with other co-occurring Neurodevelopmental Disorders.

Sex- and/or Gender-Related Features:

• Developmental Language Disorder appears to affect more boys than girls, though this gender ratio varies across clinical samples (2:1 to 6:1) and population-based samples (1.3:1).
• Boys appear to be more likely than girls to experience co-occurring Developmental Language and Developmental Speech Sound Disorders.

Boundaries with Other Disorders and Conditions (Differential Diagnosis):

• Boundary with Disorders of Intellectual Development: Individuals with Disorders of Intellectual Development may exhibit delays in language onset, development, or impairment in language abilities, accompanied by generalized impairment in intellectual and adaptive behaviour functioning. Developmental Language Disorder can occur with varying levels of intellectual ability. If the diagnostic requirements of a Disorder of Intellectual Development are met and language abilities are significantly below what would be expected based on the general level of intellectual functioning and adaptive behaviour, both diagnoses may be assigned.
• Boundary with Developmental Speech Sound Disorder and Developmental Speech Fluency Disorder: Like Developmental Language Disorder with impairment in mainly expressive language, Developmental Speech Sound Disorder and Developmental Speech Fluency Disorder can result in reduced intelligibility that significantly affects communication. Developmental Speech Sound Disorder is characterized by errors of pronunciation that are outside the limits of normal variation for chronological developmental age. Developmental Speech Fluency Disorder is characterized by disruption of the normal rhythmic flow and rate of speech. In contrast, Developmental Language Disorder is characterized by persistent difficulties in the acquisition, understanding, production or use of language.
• Boundary with Autism Spectrum Disorder: Individuals with Autism Spectrum Disorder often present with delayed language development. The extent of functional language impairment, which refers to the capacity of the individual to use language for instrumental purposes (e.g., to express personal needs and desires), should be coded using the Autism Spectrum Disorder qualifier for functional language impairment rather than using a separate diagnosis of Developmental Language Disorder. Moreover, pragmatic language impairment is a characteristic feature of Autism Spectrum Disorder even when other aspects of receptive and expressive speech are intact. Autism Spectrum Disorder is differentiated from Developmental Language Disorder by the presence of additional impairments in social reciprocity as well as restricted, repetitive and stereotyped behaviours. Unlike individuals with Autism Spectrum Disorder, individuals with Developmental Language Disorder are usually able to initiate and respond appropriately to social and emotional cues and to share interests with others, and do not typically exhibit restricted, repetitive and stereotyped behaviours. An additional diagnosis of Developmental Language Disorder should not be assigned to individuals with Autism Spectrum Disorder based solely on pragmatic language impairment. However, both diagnoses may be assigned if there are additional specific impairments in semantic, syntactic and phonological development.
• Boundary with Developmental Learning Disorder: Persistent deficits in the acquisition, understanding, production or use of language in Developmental Language Disorder may lead to academic learning difficulties, especially in literacy, including word reading, comprehension, and written output. If all diagnostic requirements for both Developmental Language Disorder and Developmental Learning Disorder are met, both diagnoses may be assigned.
• Boundary with Selective Mutism: Selective Mutism is characterized by consistent selectivity in speaking, such that a child demonstrates adequate language competence in specific social situations, typically at home, but predictably fails to speak in others, typically at school. In contrast, language difficulties associated with Developmental Language Disorder are apparent in all settings. However, Selective Mutism and Developmental Language Disorder can co-occur, and both diagnoses may be assigned if warranted.
• Boundary with Diseases of the Nervous System and sequelae of brain injury or infection: Language impairment may result from brain damage due to stroke, trauma, infection (e.g., meningitis/encephalitis), developmental encephalopathy with or without overt epilepsy, or syndromes of regression (e.g., Landau-Kleffner Syndrome or acquired epileptic aphasia). When language difficulties are a specific focus of clinical attention, a diagnosis of Secondary Speech or Language Syndrome should be assigned in addition to the associated medical condition.
• Boundary with oral language delay or impairment due to hearing impairment: All children presenting with language impairment should have an assessment for hearing impairment because language delay may be better accounted for by hearing impairment. Very young children with hearing impairment usually compensate for lack of oral language by using nonverbal modes of communication (e.g., gestures, facial expressions, eye gaze). However, presence of hearing loss does not preclude a diagnosis of Developmental Language Disorder if the language problems are disproportionate relative to the severity of hearing loss. Developmental Language Disorder can be assigned to children whose primary communication modality is through signing if exposure to and opportunity to learn sign language has been adequate and the other features of the disorder are present as they apply to sign language.
• Boundary with other medical conditions involving loss of acquired language skills: When loss of acquired language skills occurs as a result of another medical condition (e.g., a stroke), and language difficulties are a specific focus of clinical attention, a diagnosis of Secondary Speech or Language Syndrome should be assigned in addition to the associated medical condition rather than a diagnosis of Developmental Language Disorder.

Specifiers for areas of language impairment:

The main areas of language ability currently affected in Developmental Language Disorders should be characterized using one of the following specifers, although these may vary over time:

6A01.20 Developmental Language Disorder with impairment of receptive and expressive language

• This qualifier should be applied when the ability to learn and understand spoken or signed language (i.e., receptive language) is markedly below the expected level for the individual’s age and is accompanied by persistent impairment in the ability to produce and use spoken or signed language (i.e., expressive language).

6A01.21 Developmental Language Disorder with impairment of mainly expressive language

• This qualifier should be applied when the ability to produce and use spoken or signed language (i.e., expressive language) is markedly below the expected level for the individual’s age, but the ability to understand spoken or signed language (i.e., receptive language) is relatively intact.

6A01.22 Developmental Language Disorder with impairment of mainly pragmatic language

• This qualifier should be applied when the Developmental Language Disorder is characterized by persistent and substantial difficulties with the understanding and use of language in social contexts, for example making inferences, understanding verbal humour, and resolving ambiguous meaning. Receptive and expressive language skills are relatively unimpaired, but pragmatic language abilities are markedly below the expected level for the individual’s age and interfere with functional communication to a greater degree than with other components of language (e.g., syntax, semantics). This qualifier should not be used if the pragmatic language impairment occurs in the context of a diagnosis of Autism Spectrum Disorder.

6A01.23 Developmental Language Disorder with other specified language impairment

• This qualifier should be applied if the Developmental Language Disorder meets all of the diagnostic requirements of the disorder but the pattern of deficits in language is not adequately characterized by one of the other available specifers.