<unk>  is defined purely in behavioural terms: there is no biological test. There are three points that need to be met for a diagnosis of<unk> : # The child has<unk>  difficulties that create obstacles to communication or learning in everyday life, # The child's<unk>  problems are unlikely to resolve by five years of age, and # The problems are not associated with a known biomedical condition such as brain injury, neurodegenerative conditions, genetic conditions or chromosome disorders such as Down syndrome, sensorineural hearing loss, or autism spectrum disorder or intellectual disability. For research and epidemiological purposes, specific cutoffs on<unk>  assessments have been used to document the first criterion. Tomblin et al. proposed the EpiSLI criterion, based on five composite scores representing performance in three domains of<unk>  (vocabulary, grammar, and narration) and two modalities (comprehension and production). Children scoring in the lowest 10% on two or more composite scores are identified as having<unk>  disorder. The second criterion, persistence of<unk>  problems, can be difficult to judge in a young child, but longitudinal studies have shown that difficulties are less likely to resolve for children who have poor<unk>  comprehension, rather than difficulties confined to expressive<unk> . In addition, children with isolated difficulties in just one of the areas noted under 'subtypes' tend to make better progress than those whose<unk>  is impaired in several areas. The third criterion specifies that<unk>  is used for children whose<unk>  disorder is not part of another biomedical condition, such as a genetic syndrome, a sensorineural hearing loss, neurological disease, autism spectrum disorder or intellectual disability – these were termed 'differentiating conditions' by the CATALISE panel.<unk>  disorders occurring with these conditions need to be assessed and children offered appropriate intervention, but a terminological distinction is made so that these cases would be diagnosed as<unk>  disorder associated with the main diagnosis being specified: e.g.<unk>  disorder associated with autism spectrum disorder." The reasoning behind these diagnostic distinctions is discussed further by Bishop (2017). Benchmarks for children with<unk>  Common red flags at one year of age * No reaction to sound * No babbling * Difficulty feeding * No imitation * Limited use of gestures At two years of age * Makes minimal attempts to communicate with gestures or words * Has not spoken their first words * Difficulty following simple directions * Inconsistent response to "no" At three years of age * Limited use of speech * Incomprehensible speech * Limited understanding of simple questions * Difficulty naming objects * Frustration related to communication At four years of age * Uses only 3 word phrases * Speech is not understandable to parents * Takes a long time to understand others * Difficulty asking questions and finding words to express thoughts At five years of age * Speaks only in simple sentences * Speech is not understandable to teachers * Difficulty answering questions * Difficulty with complex directions * Difficulty telling stories * Difficulty with peer interactions Assessment Assessment will usually include an interview with the child’s caregiver, observation of the child in an unstructured setting, a hearing test, and standardized tests of<unk> . There is a wide range of<unk>  assessments in English. Some are restricted for use by experts in speech-language pathology: speech and<unk>  therapists (SaLTs/SLTs) in the UK, speech-language pathologists (SLPs) in the US and Australia. A commonly used test battery for diagnosis of<unk>  is the Clinical Evaluation of<unk>  Fundamentals (CELF). Assessments that can be completed by a parent or teacher can be useful to identify children who may require more in-depth evaluation. The Children’s Communication Checklist (CCC–2) is a parent questionnaire suitable for assessing everyday use of<unk>  in children aged four years and above who can speak in sentences. Informal assessments, such as<unk>  samples, are often used by speech-language therapists/pathologists to complement formal testing and give an indication of the child's<unk>  in a more naturalistic context. A<unk>  sample may be of a conversation or narrative retell. In a narrative<unk>  sample, an adult may tell the child a story using a wordless picture book (e.g. Frog Where Are You?, Mayer, 1969), then ask the child to use the pictures and tell the story back.<unk>  samples can be transcribed using computer software such as the Systematic Analysis of<unk>  Software, and then analyzed for a range of features: e.g., the grammatical complexity of the child's utterances, whether the child introduces characters to their story or jumps right in, whether the events follow a logical order, and whether the narrative includes a main idea or theme and supporting details.
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