Stability and Change in Developmental language disorder (DLD) Courtenay Frazier Norbury University College London Stockholm, October 2018

Transcription

1 Stability and Change in Developmental language disorder (DLD) Courtenay Frazier Norbury University College London Stockholm, October 2018

2 Workshop Objectives Part 1: understand diagnostic criteria for Developmental Language Disorder and associated conditions Part 2: consider impact of DLD on literacy, academic/employment and mental health outcomes Part 3: evaluate intervention and service delivery approaches how can evidence inform your practice?

3 Phonology the sounds of language Syntax/morphology the rules that control sentence formation and word endings (plural, past tense) Language Semantics the meaning of individual words & words in context Pragmatics the use of language in context & social exchanges (narrative/discourse)

4 What do you notice about: Language children are using Social communication skills How do they describe the impact of DLD?

5 Part 1: diagnostic criteria and relation to other developmental conditions

6 Developmental Language Disorder DSM5 (APA 2013) child s language abilities are below chronological age expectations language deficits are not explained by other developmental concerns such as sensory impairment, autism, extreme deprivation, head injury, global developmental delay although language impairment is frequently associated with other developmental concerns language impairments interfere with everyday life at home or at school

7 DLD arises from genetic and environmental risk factors (and the interaction between the two)

8 Genetic influences on DLD Family aggregation: rates of language/learning difficulties higher in relatives of those with language disorder, compared with controls DLD SLI control Control % affected relatives Neils, 1986 Bishop, 1986 Tallal, 1989 Tomblin, 1989

9 Twin Study Method MZ twins: genetically identical DZ twins: share 50% of polymorphic genes Question: Is concordance for disorder higher in MZ twins than in DZ twins? note: all twins living at home NOT adoption study!

10 Diagnosis in co-twins of probands with specific speech/language impairment (SSLI) SSLI low language speech therapy mental handicap MZ: n = 63 DZ: n = 27

11 Focus on identifying heritable traits e.g. non-word repetition: tegwop blonterstaping

12 Genetic influences on DLD non-word repetition highly heritable Bishop, North & Donlan (1994)

13 previously specific language impairment Or developmental dys/aphasia term SLI took hold in era of universal grammar Language is modular / innate Can be selectively impaired recent evidence suggests developing brains are not so modular

14 Disorder of language or learning? Early language learning involves multiple cortical/subcortical systems Modularity long-term outcome of learning process Propose children with DLD have deficient cortistriatal loops involving the dorsal striatum These circuits implicated in complex rule-governed LEARNING Krishnan, Watkins & Bishop (2016) Trends in Cognitive Sciences

15 Implications of biological influences: (a)better understanding of possible causal pathways (b) diagnostic criteria that reflect likely co-occurring conditions (e.g. variable non-verbal cognitive skills)

16 what looks like environmental influences on DLD may well reflect genetic vulnerability Parents of children with DLD may sometimes (not always) have language/literacy challenges themselves

17 diagnosis based on behavioural assessments and observations

18 How low can you go?

19 What aspects of language? Children with DLD can have uneven profiles of language strength and weakness OR flat profiles of deficit across multiple language domains

20 Functional impacts Poor literacy Academic underachievement At school entry: language/communication below age expectations unemployment Increased risk poor mental health Problems with peer relationships Behaviour Problems

21 Included multidisciplinary input from English speaking countries SLTs, psychologists, charities, parents, teachers, etc Agreed core diagnostic criteria and consistent terminology

22 CATALISE 2 Developmental Language Disorder is recommended as a term to replace SLI, for children with persistent disorder and poor prognosis

23 Language Disorder with Associated biomedical conditions (examples) brain injury, acquired epileptic aphasia in childhood, certain neurodegenerative conditions, genetic conditions such as Down syndrome, cerebral palsy sensori-neural hearing loss autism spectrum disorder (ASD) intellectual disability

24 Developmental Language Disorder developmental means emerges in the course of development Language will improve, but child unlikely to grow out of language problems Children with lower non-verbal IQ can be included as cases of DLD Poor prognosis Large discrepancy between verbal and non-verbal ability not required Risk factors noted, but not used as exclusions (e.g. attention, social/economic disadvantage)

25 Common objections to CATALISE recommendations What do we do about children with language delay (late talkers)? How will we cope with widening nonverbal IQ criteria? Can these children benefit from intervention?

26 Measurement of language at 2 is not reliable (on its own) Duff et al. (2015): the stability of vocabulary skills from infancy to later childhood is too low to be sufficiently predictive of language outcomes at an individual level Vocabulary at age 2 explained only 4% of variation in language outcome at ages 5-9 (and 11% of reading outcome) Bornstein et al. (2016): 15 months was too early to form reliable skill groups that predicted later outcomes. only 44% of variation in language at 5 explained by language at 25 months Prediction doubles at age 5

27 Combine language assessment with other risk factors Family history Low SES background Behaviour problems Poor language comprehension Reported language regression Global developmental delay Lack of gesture Poor social engagement Male sex

28 role of non-verbal abilities in speech-language therapy Non-verbal ability single most common reason children with language disorders refused access to specialist speechlanguage therapy or placement in language units in the UK (Dockrell et al. 2006) Yet non-verbal ability key risk factor for persistent & severe language disorder (Bishop & Edmundson, 1987; Conti- Ramsden et al. 2012)

29 what is the causal relationship of language and non-verbal ability? language is a fantastic problem solving tool!!

30 Non-verbal ability In most longitudinal studies, NVIQ does NOT predict rate of growth (Norbury et al. 2017; Bornstein et al. 2016) We lack intervention studies that systematically explore NVIQ as moderator of treatment effects Language intervention can benefit children with intellectual disabilities (Burgoyne et al. 2012)

31 How many children start school with language deficit? What is impact of language deficit on other aspects of learning &

32 Prevalence Year 1 % of population Language Disorder (cause unknown) 7.58% Language Disorder (known cause and/or intellectual impairment) higher NVIQ 4.80% lower NVIQ 2.78% 2.34% Total Language Disorder 9.92% Fewer than 12% meet early curricul um targets

33 Clinical profile by diagnosis & non-verbal IQ band Low NVIQ (>-2SD & <-1SD) High NVIQ (>= -1SD) Lang Disorder+ IDACI rank Communication checklist Language composite (z-score) % Social, emotional, behavioural probs Academic attainment % referred to SLT

34 From school entry language is stable 0 2 Total Language Year 3 (z-score) From school entry, language is stable Better than Year 1? -4-2 Worse than Year 1? z_total_comp y Total Language Year 1 (z-score) ICC =.95

35 Social disadvantage, behaviour problems & low non-verbal do NOT predict Language improves, but not enough to narrow the gap with TD peers Typical children LD other 2-3 year language gap between those at the top and the bottom of the distribution DLD unknown cause

36 DLD: summary Language is below age expectations with evidence of functional impact and poor prognosis Non-verbal abilities are not considered in diagnosis (and should not dictate treatment options) DLD is influenced by both genetic factors and environmental factors Language (and language disorder) are stable traits language may improve but in DLD, skills relative to peers remain impaire

37 Part 2: consider impact of DLD on literacy, academic/employment, and mental health outcomes

38 Identifying DLD in the classroom =JAsf_Wqjz4g

39 The fearful roaring of the dragon guided the Knight to the monster's territory. As the intruder crossed the dreaded marshes, the dragon charged furiously, whipping its enormous tail around the legs of the Knight's steed. Horse and rider collapsed. The Knight now realised that he must attack when the creature was off-guard. He crouched as though wounded. The monster, accustomed to speedy victory, prepared to seize its prey. Then the Knight struck powerfully beneath the beast s outstretched wings. The villagers would be troubled no more.

40 How did the knight know exactly where to find the dragon? What kind of land did the knight have to cross? How did the dragon knock the knight down? What did the knight pretend to do? Why did the dragon think its first blow would kill the knight? Why were the people in the village pleased?

41 What language skills did you need to do this task?

42 The fearful roaring of the dragon guided the Knight to the monster's territory. As the intruder crossed the dreaded marshes, the dragon charged furiously, whipping its enormous tail around the legs of the Knight's steed. Horse and rider collapsed. The Knight now realised that he must attack when the creature was off-guard. He crouched as though wounded. The monster, accustomed to speedy victory, prepared to seize its prey. Then the Knight struck powerfully beneath the beast s outstretched wings. The villagers would be troubled no more.

43 autism spectrum conditions DLD autism spectrum conditions Adapted from Bishop & Snowling (2004)

44 Improving oral language has positive impact on reading comprehension. York Reading for Meaning Project Clarke et al. (2010) Psych Science

45 ReadMe: Oral language programme Developing vocabulary (multiple contexts) Figurative language (jokes, metaphors, idioms, similes) Listening comprehension (reciprocal teaching) clarify, summarise, predict, question Story-telling (story mountain) Opening, build-up, problem, main event, resolution, ending

46 ReadMe: comprehension outcomes All groups show increase in reading comp scores Oral language only group show greatest change but only at followup! Clarke et al. (2010) Psych Science

47 Impact of DLD not limited to literacy outcomes 06 Self-confidence and self-awareness: Children are confident to speak to a class group. They can talk about the things they enjoy, and are good at, and about the things they do not find easy. They are resourceful in finding support when they need help or information. They can talk about the plans they have made to carry out activities 07 Managing feelings and behaviour: Children know some ways to manage their feelings and are beginning to use these to maintain control. They can listen to each other s suggestions and plan how to achieve an outcome without adult help. They know when and how to stand up for themselves appropriately. They can stop and think before acting Making relationships: Children play group games with rules. They understand someone else s point of view can be different from theirs. They resolve minor disagreements through listening to each other to come up with a fair solution.

48 Impact of DLD not limited to literacy outcomes 11 Numbers: Children estimate a number of objects and check quantities by counting up to 20. They solve practical problems that involve combining groups of 2, 5 or 10, or sharing into equal groups. 12 Shape, space and measures: Children estimate, measure, weigh and compare and order objects and talk about properties, position and time. 14 The world: children know about similarities and differences in relation to places, objects, materials and living things. They talk about the features of their own immediate environment and how environments might vary from one another. They make observations of animals and plants and explain why some things occur, and talk about changes.

49 At school entry Early Years Foundation Stage Profile Children who start school with language problems very unlikely (<5%) to meet early curriculum targets Norbury et al. (2016) JCPP

50 At the end of formal schooling: GCSE Attainments Typical language Resolved DLD Persistent DLD % gaining A-C pass Snowling et al. (2011)

51 Language and mental health outcomes Emotional Anxiety, Depression ~1 per class (3.7%) Behavioural ODD, Conduct Disorder Risk factor for incarceration ADHD Attention Deficit Hyperactivity Disorder 42.5 Billion USD in 2003

52 Children with (history) of language disorder at twice the risk of one of these three adverse mental health outcomes by adolescence.

53 trajectory of behaviour in children with DLD receptive and pragmatic language deficits associated with poor behaviour St Clair et al. (2011) Potential interactions with socio-economic status, non-verbal IQ, and school placements/experiences

54 language and mental health: what are the causal links? establish & maintain social relationships language articulate feelings, selftalk to regulate emotional state mental health self-talk to manage own/other behaviour verbalise goals/rules

55 Part 2: DLD impacts summary DLD is associated with: Academic underachievement at all stages of education Language is central to learning in all aspects of the curriculum Literacy is especially challenging Poorer social, emotional, and mental health