Autism Spectrum Disorder (ASD) is a neuro-developmental condition that is characterised by impairments in social interaction, communication and repetitive behaviours. The condition affects almost one in every 100 children. Over the last few years there has been an increase both in the early diagnosis of ASDs and in the range of effective interventions available for children. In Ireland, parents of young children are entitled to an assessment of their child’s needs, but their children have no automatic entitlement to receive therapeutic interventions. One of the consequences of the ever-decreasing health and education budgets is that resources are now being concentrated on the provision of statutory ‘assessments of need’, and not on effective interventions and supports. This is leading to increased frustration on the part of both parents and service providers.
This article looks at one child-centred, play-based intervention for young children with autism. The Early Start Denver Model (ESDM) was developed for toddlers as young as 12 months. It is an adapted extension of the original Denver Model for preschoolers with autism aged 24-36 months, which combines the development of responsive relationships with behavioural teaching techniques. The Model aims to reduce the severity of autism symptoms and accelerate children’s progress in all areas of development, but particularly cognitive, social.emotional and language development so as to enable children enjoy a better quality of life.
ESDM brings together a number of complementary approaches which focus on teaching skills that follow typical patterns of child development. Each of these approaches views autism as resulting from impediments in infants’ early interpersonal experiences, which creates barriers to social.communication development.
The original Denver Model views autism as resulting primarily from a failure in the area of social-communication development. Accordingly, intervention is focused on care givers building close relationships with children using lively, dynamic interactions. These interactions involve a strong positive affect to encourage children to seek out others for interaction during favourite activities. Rogers and Pennington’s ‘Model of Interpersonal Development in Autism’ posits that infants with autism are impaired in their ability to imitate and attune with the feelings of others. This creates barriers for the development of an understanding of emotional sharing and intentional communication. Intervention in this model is directed at addressing these critical impairments in development, though fostering emotionally rich relationships with responsive, sensitive others who attune to and coordinate with the child’s emotional state. The ‘Social Motivation Hypotheses of Autism’ holds that the reason people with autism spend less time attending to and interacting with others is because of their lack of sensitivity to social rewards early in life. This results in a failure on their part to attend to and engage with others, which (over time) leads to people with autism becoming more and more removed from the social world around them. Interventions in this model are aimed at increasing the salience of social rewards so as to enhance the child’s social attention and motivation for social interaction.
These approaches are combined with Pivotal Response Training (PRT) to form ESDM for teaching children with autism. PRT is based on the principles of applied behavioural analysis (ABA) and was developed to optimise children’s motivation to interact with adults and engage in repeated learning opportunities.
The ESDM curriculum
ESDM involves a developmental, broad-based curriculum that addresses the areas of imitation, joint attention, social interaction, play, receptive and expressive communication, cognition, self-care, and gross and fine motor skills. Each child is evaluated using the curriculum checklist. Based on this assessment, individual learning objectives are devised to focus on the child’s and family preferences and interests. Daily data sheets are used to record progress. Initial objectives are reviewed and new ones set every twelve weeks. If progress is slow, the therapist uses the ESDM decision tree to enable him or her to make necessary systematic changes to the teaching procedure.
The language intervention approach used comes from the science of communication development, rather than from behaviour analysis; it recognises that verbal language develops from nonverbal social-communication behaviours as well as speech sounds. People use verbal and nonverbal communication to coordinate their activities and to share their inner lives involving intentions, desires, interests, thoughts and feelings. The ESDM intervention provides multiple and varied communicative opportunities and elicits many communicative behaviours, both verbal and nonverbal, from the child during each intervention session. The range of communicative, or pragmatic functions, is carefully developed so that a child not only requests an activity, but also protests, greets familiar adults, shares attention, and comments or narrates during an activity. Spontaneous communication is carefully supported and the child’s communications exert much control over interactions and activities, which show the child the power of communication and ensure that communication is strongly reinforced.
Complex developmental skills that are usually impaired in youngsters with autism, such as joint attention, imitation, language and symbolic play, are taught by embedding them in highly preferred activities. These skills are built up from the simplest steps to the most complex, according to their developmental sequence. Complex skills, such as eye contact, are not taught in isolation but are linked with other skills such as play and language, as this is what usually happens for typically developing children.
The ESDM is designed to be implemented by a team of professionals and family members. The team leader and parents are at the hub of the treatment team and these are supported by other professionals, such as special educators, psychologists, SLTs, OTs, behaviour analysts and physicians.
Children’s objectives are taught through play activities. During a typical session the child is given many opportunities to acquire several objectives from different developmental areas. The ESDM uses teaching practices and procedures melded together from three intervention traditions: ABA, PRT and the Denver Model. Within ESDM, basic practices of effective teaching used from ABA include: functional assessment, delivering teaching within an antecedent-behaviour-consequence sequence, capturing the child’s attention, prompting, shaping, chaining, fading, and managing consequences. Elements of PRT included are: child choice, turn taking, reinforcing attempts, using reinforcers that have a direct natural relation with the child’s response or behaviour, and interspersing acquisition and maintenance skills. The remainder of the teaching practices used come from the Denver Model. These focus on the affective and relationship-based aspects of the therapist’s work with the child, the emphasis on development of play skills, and use of communication intervention principles from the fields of communication science.
When combined, the techniques outlined above are designed to engage the child in positive emotional experiences with another person, to draw the child’s attention to social cues, to make such cues rewarding for the child, and to foster the child’s motivation to continue such activities. Therapists use these techniques to elicit social and communicative behaviours from the child that are as close to those evident in typical development.
Evidence of effectiveness
A number of papers have been published in peer-reviewed journals showing the effectiveness of the original Denver Model or ESDM as an intervention for children with autism. This article focuses on just one of these publications, owing to its exceptional quality in the field of autism intervention research. Geraldine Dawson, Sally Rogers and colleagues in the US conducted a randomised, controlled study to investigate the effectiveness of the ESDM as an intervention for toddlers with autism. Forty.eight children with an ASD between 18 and 30 months were randomly assigned to one of two groups: (1) an ESDM intervention group, or (2) commonly available community interventions (control group). The ESDM received yearly assessments, parent training, 15 hours per week (on average) of the ESDM intervention from clinicians, and a further 16 hours per week (on average) of ESDM intervention delivered by parents. In addition, children received whatever community services the parents chose during the two years. The control group received yearly assessments with intervention recommendations and were referred for intervention to commonly available community providers in the region (i.e. greater Seattle, Washington). Children were evaluated by experienced examiners prior to intervention, one year after the start of intervention, and again after two years or at 48 months of age—whichever yielded a longer time frame. The examiners were unaware of the intervention groups that the children had been assigned to and this helped prevent the possibility of examiner bias influencing the results. The ESDM detailed intervention manual and curriculum were used with the ESDM intervention group. One or both parents were provided with parent training during semi-monthly meetings. Programme integrity checks were carried out to ensure that clinicians implemented the ESDM intervention with a high level (85% +) of fidelity. Results show that there was a significant difference between the two groups in IQ, adaptive behaviours (e.g. communication, daily living skills, socialisation and motor skills), and autism diagnosis following two-years of intervention. Two years after starting intervention, the ESDM group showed an average increase in IQ of 17.6 points compared with 7 for the other group. Those in the ESDM group showed greatest progress in the areas of expressive and receptive language. The ESDM group made steady progress in the area of adaptive behaviour over the course of the research, while the control group displayed an 11.2 point average decline in standard scores on the Vineland Adaptive Behaviour Scales. Children in the ESDM group were significantly likely to have improved diagnostic status following two years of intervention, compared with those in the control group.
Similarities and differences with other interventions
The ESDM most closely resembles other popular autism interventions approaches that place a strong emphasis on responsive interactions and developmental orientation. These include DIR/Floortime, Relationship Development Intervention/ RDI, SCERTS, Marte Meo and Hanen. All of these interventions are built on evidence about typical social-communicative development. The ESDM uses more clearly stated behavioural techniques than the other approaches, it is more data driven, and it covers all developmental areas, while most of the other models focus on social-communicative development.
The ESDM has clear ties to the naturalistic behavioural interventions like PRT, incidental teaching and milieu teaching, all of which also use a child-centred, natural language frame delivered using behavioural teaching strategies. The ESDM differs from these, however, in the emphasis placed on affect and quality of relationship.
Finally, the ESDM is similar to the Lovaas/UCLA Young Autism Project approach, in so far as both have a broad-based curriculum, use intensive behavioural approaches, and collect and use data to monitor progress and inform decision making. It differs from the Lovaas approach in the child.versus adult.centred teaching approach used, the focus on child positive affect, the focus on teaching communication embedded in ongoing social interaction and on nonverbal communication as a precursor to verbal communication and in its use of a curriculum based on developmental science.
There are no comparative studies that show that ESDM is better than other effective approaches for children with autism, so it is not possible to provide information on which approach is ‘best’. However, it is unlikely that any one approach will suit all children with autism. What is needed are intervention approaches that fit the family’s preferred way of interacting with children, a teacher and a therapist’s most successful way of interacting with others, and a child’s own profile.
The main principles of the ESDM result from a sophisticated combination of evidence from studies of early autism, studies of typical infant and child development, and studies of learning. The ESDM fills a current need in the field for a rigorous, evidenced-based intervention that uses a developmental relationship-based, and data-based approach to address the many developmental needs of young children with ASD and the needs of their family.