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The early signs of autism in toddlers

Key learning points:

- Health visitors and primary care nurses have an important role in identifying children who may later be diagnosed with autism

- Issues relating to a range of early social communication skills and stereotyped, repetitive and restricted behaviours may be predictive of risk for autism from as early as 12 months of age

- Support for parents is crucial prior to, during and following the diagnostic process

Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition which affects the way an individual communicates with and understands others, and typically involves intense interests or preoccupations, stereotyped and repetitive patterns of behaviour and a variety of sensory issues.

Current estimates suggest that approximately 1% of the population have ASD.1 Around half will have intellectual ability within the average range, and may be described as having Asperger's syndrome or high functioning autism. The remainder will have some degree of learning disability, may be non-verbal or have limited or delayed speech, and will often require some degree of lifelong specialist support. As with most developmental conditions, ASD is more prevalent in males than females, although the male-to-female ratio varies from approximately four to one in more profoundly affected individuals with lower intellectual ability, to around ten to one for those with a more Asperger-type profile.2

Defining autism

Autism is a very heterogeneous condition, but the main features observed in children, adolescents and adults with ASD are increasingly well understood amongst both professionals and
the population in general. These features include, but are not limited to:

- Difficulties engaging in reciprocal conversation.

- Restricted use and understanding of non-verbal communication skills, such as gestures, facial expressions and intonation.

- Unusual use of speech, including echolalia, repetition of words and phrases out of context and pronoun reversal.

- Problems with emotional regulation and engaging in peer relationships.

- Intense interest in specific non-functional routines and activities.

- A preference for predictable routines and negative responses to unexpected change.

- Limited imaginative and pretend play.

- Hypo and hypersensitivity to a range of visual, auditory, olfactory and tactile stimuli.

A range of positive features are also commonly observed in people with autism, including perfect recall, attention to detail, excellent visual skills and originality in cognitive style and creative ability.

Early signs of autism

Despite the increasing level of knowledge of the main features associated with individuals diagnosed with autism, the understanding of the precursors to the condition (the so-called 'prodrome' of autism)3 is not so well developed. Autism can be diagnosed reliably from the age of three - earlier in more clear-cut cases, but individuals with a profile associated with Asperger syndrome may not be identified until they start attending school, after moving to secondary school, or even into adulthood.

Initial parental concerns about children subsequently diagnosed with ASD often relate to the delayed onset of speech, which becomes more apparent during the second year of life. In hindsight, parents often report that their child did not babble or vocalise in a social way. Sometimes parents realise that their child did not engage in the rhythmic to-and-fro 'dance' of reciprocal smiling, vocalising and movement that is common in typical early social development. Whether or not parents have been worried about their child's development, attendance at playgroup, nursery or preschool can highlight difficulties in children who may have ASD, particularly those relating to interacting with other children, adapting to new routines and expectations of behavioural and emotional self-management.

So-called 'babysib' studies, involving babies who, at birth, have an older sibling with a diagnosis ASD, are one approach to clarifying the earliest signs of autism. Participants are assessed periodically, using a range of clinical and experimental techniques, generally until they are three years old. Outcomes from these studies suggest that as many as 10% of participants may eventually be diagnosed with ASD4 - a figure attributable to the strongly genetic and heritable nature of autism. There is evidence of differences from as young as six months of age, but these are based on the results of experimental tasks involving EEG, MRI or eye tracking techniques.5,6

Differences based on clinical observation, parental report and other behavioural measures start to emerge from 12 months onwards. Language and social communication behaviours that may be reduced in frequency in young children later diagnosed with ASD include looking at others' faces, social smiling and vocalising.7 Factors based on parent report measures that distinguish ASD from typical development in toddlers also relate to concerns about social communication skills and repetitive, stereotyped or unusual behaviours and interests.8,9

Screening, referral and diagnosis

Over the past 20 years or so, a number of autism-specific screening tools have been developed, but on the whole these have not been shown to have adequately robust properties to be used in a community-wide context,10 and their routine use is not recommended by the UK National Screening Committee.11 There is a growing consensus that ongoing surveillance, rather than a 'one-hit' screening approach is more effective and desirable,12 although this will have considerable resource implications.

Clearly, there may be a number of reasons why infants and young children do not develop speech which are not associated with autism, and referral to speech and language therapy and/or audiology services will often be appropriate. If a speech and language therapist believes that a young child has ASD, they will generally be allocated to a social communication care pathway, which would include referral to the local child development centre (CDC) plus pre-diagnostic intervention. In many cases early years professionals including doctors, health visitors and nursery staff may request that the local authority carries out an assessment relating to an education, health and care (EHC) plan,13 which aims to identify the child's education, health and social needs and set out any additional support required to meet those needs.

In accordance with the National Institutes of Care and Excellence (NICE) guidelines,14 differential diagnosis of toddlers with a suspected developmental disorder should be carried out within a local multidisciplinary team - typically part of the CDC or equivalent. Evidence contributing to the diagnosis should include at least the following three components:

- Observation of the child in a nursery or other group setting.

- Direct assessment of the child's language, communication, social interaction and play skills.

- Interviews with parents about developmental history and factors relating to autistic symptomatology.

In most cases assessment includes gold standard diagnostic assessments such as the autism diagnostic observation schedule (ADOS),15 and interviews such as the autism diagnostic interview - revised (ADI-R)16 or the developmental, dimensional and diagnostic interview (3Di).17 However, as these instruments cannot provide perfect categorisation, diagnosis must ultimately be based on the clinical judgement of experienced clinicians.14

Further investigations are appropriate if additional neurodevelopmental, physiological or medical conditions appear to be present. Conditions for which differential diagnosis may be required include:

- Language delay or disorder, including specific language impairment (SLI).

- Speech and articulation difficulties.

- Attention deficit hyperactivity disorder (ADHD).

- Developmental co-ordination disorder (DCD).

- Global developmental delay.

- Mood disorder.

- Attachment disorder.

- Anxiety disorder.

- Obsessive compulsive disorder (OCD).

Some of these conditions may co-occur with ASD, and some may not generally be diagnosed reliably until after the preschool years (ADHD for example).



There is a range of interventions that are appropriate for pre-schoolers who have been identified as having a probable ASD, but who have yet to be formally diagnosed. Many of these focus on helping parents and carers to identify the child's functional communication skills, engage in shared attention, promote 'joyful interaction' and enhance the child's readiness for learning. Some of these parent-mediated approaches involve specific manualised programmes, such as Hanen,18 but many are more generic parent-child interaction interventions offered via local speech and language therapy teams and other early years services. Home based provision such as Portage19 and communication or behaviour focused programmes will also often be available.


A variety of autism-specific approaches and interventions may be available following diagnosis. This includes a number of parent mediated interventions similar to those described above, but provide more explicit guidance and support relating to autism. Examples of these include 'EarlyBird',20 the more than words programme21 and relationship development intervention (RDI).22 Parent-mediated interventions are often provided as courses to small groups of parents and include home-based visits to observe and support parent-child interaction. The evidence base for this approach is expanding but has not yet demonstrated unequivocally the effectiveness of parent-mediated developmental treatments.

Another group of approaches are those based on applied behavioural analysis (ABA), including autism-specific examples such as the Lovaas approach23 and the picture exchange communication system (PECS).24 In contrast to developmental approaches these didactic interventions aim to teach specific core skills, including responding to instructions and questions, and incorporate behavioural techniques such as reinforcement.

One other approach which has been increasingly provided in early years settings for children on the autism spectrum is attention autism,25 which aims to provide children with fun and engaging stimuli to facilitate readiness for learning and tolerance for group activities. There have been no reported attempts as yet to formally evaluate this approach. The whole range of treatments and interventions that have been designed for or used with individuals with autism, including medical, behavioural and alternative approaches, is described on the Research Autism website, which provides impartial summaries of the evidence relating to these.26

Supporting families

Coming to terms with the fact that a child has any form of disability or developmental disorder can be extremely stressful for parents. Early years professionals including health visitors, nursery and children's centre staff and speech and language therapists play a vital role in supporting and guiding parents through this time.12

Prior to diagnosis professionals must be extremely careful not to pre-empt any diagnostic decision, and may need to avoid using the 'a-word' until a formal diagnosis has been made. In many cases, parents may not yet realise that their child has a developmental disability. Being made aware of this is likely to cause distress, and they may need time to come to terms with the situation.14 The confirmation that a child has autism must be presented clearly and sensitively with information about the implications of the diagnosis and immediate sources of help provided in a timely manner.14

Different families will present with a whole range of situations, experiences and levels of knowledge. In some cases the child may be the parents' first, and their knowledge and expectations of typical development may be fairly limited. On the other hand, some families will already have one or more children diagnosed with ASD, and may be fully aware of the common signs of autism. In some cases such parents may not be anxious about the prospect of the child in question having autism. Whatever the situation, professionals must show an awareness of the sensitivity around suggesting that a child has an ASD.


Autism Speaks-

The NICE guidelines (autism spectrum disorders)-

Research Autism


1. Centers for Disease Control and Prevention. Prevalence of Autism Spectrum Disorders — Autism and Developmental Disabilities Monitoring Network, 14 Sites, United States, 2008. Morbidity and Mortality Weekly Report. Surveillance Summaries; 61(3). 2012

2. Mandy W, Chilvers R, Chowdhury U, Salter G, Siegal A, Skuse D. Sex differences in autism spectrum disorder: Evidence from a large sample of children and adolescents. Journal of Autism and Developmental Disorders. 2012;42:1304-1313

3. Yirmiya N, Charman T. The prodrome of autism: Early behavioral and biological signs, regression, peri- and post-natal development and genetics. Journal of Child Psychology & Psychiatry. 2010;51:432-458

4. Zwaigenbaum L, Bryson S, Lord C, et al. Clinical assessment and management of toddlers with suspected autism spectrum disorders: Insights from studies of high risk infants. Pediatrics. 2009;123:1383-1391

5. Elsabbagh M, Mercure E, Hudry K, et al. Infant neural sensitivity to dynamic eye gaze is associated with later emerging autism. Current Biology. 2012;22:338-342

6. Gliga T, Bedford R, Charman T, Johnson MH, the BASIS Team. Enhanced visual search in infancy predicts emerging autism symptoms. Current Biology. In press

7. Ozonoff S, Iosif A, Baguio F, et al. A prospective study of the emergence of early behavioral signs of autism. Journal of the American Academy of Child & Adolescent Psychiatry. 2010;49:256-266

8. Sacrey LR, Zwaigenbaum L, Bryson S, et al. Can parents' concerns predict autism spectrum disorder? A prospective study of high-risk siblings from 6 to 36 months of age. Journal of the American Academy of Child & Adolescent Psychiatry. In press

9. Pasco G, Allison C, Baron-Cohen S, Johnson MH, Charman T. Social but not repetitive scores on the Quantitative Checklist for Autism in Toddlers (Q-CHAT) predict later autism spectrum diagnosis in a prospective high-risk sibling study. Presented at the International Meeting for Autism Research. Salt Lake City, May 2015

10. Al-Qabandi M, Gorter JW, Rosenbaum P. Early autism detection. Are we ready for routine screening? Pediatrics. 2011;128:211-217

11. UK National Screening Committee. The UK NSC recommendation on autism screening in children. (accessed 15 Jun 2015)

12. Barbaro J, Ridgway L, Dissanayake C. Developmental surveillance of infants and toddlers by maternal and child health nurses in an Australian community-health setting. Promoting the early identification of autism spectrum disorders. Journal of Pediatric Nursing. 2011;26:334-347

13. UK Government. Educational and health care plans (accessed 15 Jun 2015)

14. National Institute for Health and Care Excellence. Autism diagnosis in children and young people: Recognition, referral and diagnosis of children and young people on the autism spectrum. (accessed 15 Jun 2015)

15. Lord C, Rutter M, DiLavore PC, Risi S, Gotham K, Bishop S. The Autism Diagnostic Observation Schedule - Second Edition. Western Psychological Services: Torrance, CA

16. Lord C, Rutter M, Le Couteur A. The Autism Diagnostic Interview - Revised: A revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Journal of Autism & Developmental Disorders. 1994;24:659-685

17. Skuse D, Warrington R, Bishop D, et al. The Developmental, Dimensional and Diagnostic Interview (3di): A novel computerized assessment for autism spectrum disorders. Journal of the American Academy of Child & Adolescent Psychiatry. 2004;43:548-558

18. The Hanen Centre. It Takes Two to Talk. (accessed 15 Jun 2015)

19. The National Portage Association. (accessed 15 Jun 2015)

20. The National Autistic Society. EarlyBird.  (accessed 15 Jun 2015)

21. The Hanen Centre. More Than Words - The Hanen Program for parents of children with autism spectrum disorder.  (accessed 15 Jun 2015)

22. RDI Connect. About RDI. (accessed 15 Jun 2015)

23. The Lovaas Institute. The Lovaas Approach.  (accessed 15 Jun 2015)

24. Pyramid Educational Consultants UK Ltd. The Picture Exchange Communication System. (accessed 15
Jun 2015)

25. Gina Davies Autism Centre. Attention Autism. (accessed 15 Jun 2015)

26. Research Autism. Interventions, treatments and therapies for autism. (accessed 15 Jun 2015)