What is The Early Start Denver Model (ESDM)?

The Early Start Denver Model (ESDM) is an intervention model that has adopted the use of ABA principles, Intensive Behavioural Intervention (IBI) and naturalistic teaching. It uses a comprehensive developmental and behavioural intervention framework for the assessment and intervention process for young children with ASD. Goals are derived from assessing the child’s developmental skills and treatment is provided using the principles of ABA, (Antecedent, Behaviour and Consequence -ABC). It incorporates teaching principles from Pivotal Response Training (PRT, Hanen “More Than Words”, PECS, Prompt, Direct Floortime, etc).

ESDM views ASD as a complex disorder affecting all areas of functioning and therefore believes it requires an interdisciplinary approach (Psychology, Speech-Language Pathology, Occupational Therapy, Physician etc). Teaching can occur inside typical family routines (i.e., meals, bathing, playtime, chores, community outings etc), and targets all affected areas of development:

  • Receptive Communication
  • Expressive Communication
  • Social Skills
  • Cognition
  • Play
  • Fine Motor
  • Gross Motor
  • Personal Independence (General, Hygiene, Chores)


Why ESDM? What is the Research to support it?

A randomized controlled clinical trial of ESDM was conducted by Dawson and Colleagues out of the University of Washington and published in the Journal of Pediatrics in 2009. For the study, which was funded by a grant from the National Institute of Mental Health, Dawson, Rogers and colleagues recruited 48 children with autism aged between 18 and 30 months old. None of the children had other health problems.

The researchers put the children into two groups. One group received 20 hours a week of intervention following the Early Start Denver Model(ESDM) for two years (comprising 2 x 2 hour sessions on five days a week, delivered by specialists from the university, plus 5 hours a week of parent-delivered therapy).

The other group of children underwent therapy in community-based programs.
At the start of the study period there was no substantial difference in functioning between the groups. Both groups were similar in their baseline in severity of autism symptoms, gender, IQ, and socioeconomic status.

The results showed that:

  • Compared to the children who had the community-based intervention, the children in the ESDM group showed significant improvements in IQ, adaptive behaviour and autism diagnosis.
  • Two years after starting the intervention, the ESDM children on average improved 17.6 standard score points (one standard deviation: 15 points) compared with 7.0 points in the community-intervention group, relative to their baseline scores.
  • The children who had ESDM had an average improvement in IQ of approximately 18 points compared to little more than 4 points in the community-intervention group.
  • The ESDM group also showed a nearly 18 point improvement in receptive language (listening and understanding) compared to about 10 points in the community-based group.
  • The adaptive behaviour in the ESDM group continued to grow compared with a normative sample of typically developing children.
  • In contrast, over the same 2 year period, the community-intervention group showed greater delays in adaptive behaviour.
  • Seven of the children in the ESDM group had enough improvement in overall skill to warrant a change in diagnosis from “autism” to the milder condition known as “pervasive developmental disorder, not otherwise specified”.
  • This compared to only one child in the community-base group having an improved diagnosis.
  • The researchers concluded that the findings underscored “the importance of early detection of and intervention in autism”.Rogers explained that they believed the ESDM group “made much more progress because it involved carefully structured teaching and a relationship-based approach to learning with many, many learning opportunities embedded in the play.””Parental involvement and use of these strategies at home during routine and daily activities are likely important ingredients of the success of the outcomes and their child’s progress,” said Dawson.Furthermore, in a follow up study published in the Journal of the American Academy of Child and Adolescent Psychiatry in November, 2012, Dawson and colleagues showed that this same ESDM group showed normalized EEG brain activity demonstrating that early intervention using the ESDM model alters the trajectory of brain development. “Early Behavioural Intervention is Associated with Normalized Brain Activity in Young Children With Autism.” Geraldine Dawson, Emily Jones, Kristen Merkle, Kaitlin Venema, Rachel Lowy, Susan Faja, Dana Kamara, Michael Murias, Jessica Greenson, Jamie Winter, Milani Smith, Sally Rogers, Sara Webb. Journal of the American Academy of Child and Adolescent Psychiatry, Nov 2012. Volume 51, Number 11.
    “Randomized, Controlled Trial of an Intervention for Toddlers With Autism: The Early Start Denver Model.”
    Geraldine Dawson, Sally Rogers, Jeffrey Munson, Milani Smith, Jamie Winter, Jessica Greenson, Amy Donaldson, and Jennifer Varley.
    Pediatrics, Nov 30 2009. Vol 125, No. 1

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What is the ideal amount of ESDM?

Based on the research described above,

Ideally, 4 hours of intensive ESDM provided 5 days per week (i.e., 20 hours per week) over a two year period can produce gains in:

  • IQ
  • Language
  • Adaptive Behaviours
  • Normalized Brain Activity on EEG

What is ABA and IBI services

Autism Spectrum Disorder (ASD) is characterized by impairments in social interaction and communication and stereotyped and repetitive behaviours.

On March 27, 2014, the Centers for Disease Control and Prevention (CDC) released new data on the prevalence of autism in the United States. This surveillance study identified 1 in 68 children (1 in 42 boys and 1 in 189 girls) as having autism spectrum disorder (ASD).

It is now widely acknowledged that the form of treatment with the most empirical validation for effectiveness with individuals with ASD is applied behaviour analysis (ABA) delivered in a naturalistic teaching model.

ABA is the science devoted to understanding the laws by which environmental events influence and change behaviour. For individuals with ASD, these behaviours typically include language and communication, social and play skills, cognitive and academic skills, motor skills, independent living skills and problem behaviour.

ABA first appeared in the late 1960’s, when researchers such as Lovaas used this science to improve maladaptive behaviours of children with Autism. These programs led to increased language, social, play and academic skills and reduced some of the severe behavioural problems associated with the disorder.

ABA was used in the behavioural approach called discrete trial training (DTT) or Early Intensive Behavioural Intervention (EIBI) when delivered before the child was 5 years in age. It involved breaking down complex skills and teaching each sub-skill through a series of highly adult-structured, massed teaching trials.

These trials were typically delivered in blocks over the course of 20-40 hours per week for two or more years, with skill emphasis in communication, social skills, cognition and pre-academic skills (e.g., letter and number concepts etc).

However, despite promising results using DTT, concerns arose relating to:

  1. The adult-directed nature of the instruction and therefore lack of spontaneous use of the skill
  2. highly structured teaching environment and use of artificial or unrelated reinforces leading to lack of generalization to a natural environment and rote responding.
  3. amount of staff time
  4. the use of punitive procedures following inaccurate responses.

As a result of the above difficulties associated with DTT, new interventions were developed that include more naturalistic, spontaneous types of learning situations that embed the child’s interest and teaching opportunities. The most rigorously assessed of these programs is the Early Start Denver Model (ESDM).

ESDM is an intervention model that uses the ABA teaching framework/technique to administer intervention in a naturalistic environment (i.e., through play). This approach shows the best results when provided intensively (minimum of 20 hours/week). As such, we provide this intervention using the same principles as Intensive Behavioural Intervention (IBI), except it is conducted using naturalistic teaching. It uses a comprehensive developmental and behavioural intervention framework for the assessment and intervention process for young children with ASD. Goals are derived from assessing the child’s developmental skills and treatment is provided using the principles of ABA, (Antecedent, Behaviour and Consequence -ABC).

What Treatment Approaches are Recommended for children with Autism Spectrum Disorder?

What is the best treatment?
Research over the past 20 years has consistently shown the importance of giving children with ASD early intervention. The brain is more easily changed at an early age and patterns of restricted behaviour are not so entrenched. Currently research suggests children gain the most benefit from intensive therapy up to the age of 6 years of age.

Research suggests that, when evidence-based intervention is provided early (commencing before child is 2.5years) and intensively (20-40hours) for at least 2 years, normalization of brain activity related to social processing is possible.

It is suggested that parent and significant people in the child’s life are involved in the treatment and that the total number of hours the child is receiving evidenced-based programs is 20-40 hours/week.

Evidence Based Treatment
A number of approaches have been shown to be effective in making developmental gains in children with ASD. These include:

  • Early Start Denver Model (ESDM)
  • Intensive Behavioural Intervention /Applied Behaviour Analysis (ABA)
  • Pivotal Response Training (PRT)

Other treatment techniques, such as Picture Exchange Communication System (PECS), PROMPT (treatment for Apraxia of Speech),Hanen-More Than Words, Floortime DIR, andSensory integration Therapy can be used using ABA methodology within PRT, IBI and/or ESDM. Given that 65% of children with Autism have a dual diagnosis of Apraxia, PROMPT is integral to the treatment approach within any Autism program.

Simone Friedman SLS Approach
We use formal behaviour modification (ABA) to teach developmental skills within a naturalistic play-based context using the ESDM model. We provide intensive (IBI) 4-9 hour programming daily, collecting data and graphing results. If TPAS approved and DFO funded, our DFO approved consulting psychologist will oversee the IBI program.

As a trans-disciplinary clinic, we have the means to work on a number of skills, such as, but not limited to:

  • Communication
  • Social Skills
  • Behaviour
  • Gross & Fine Motor Skills
  • Self Help
  • Cognition
  • ADL’s
  • Play
  • Life Skills
  • Articulation/Apraxia

Services Offered

Treatment programs are tailored for each and every child we treat, according to the child’s abilities and age.

Programs may include one or more of the following service options:

Individual Therapy Sessions (S-LP & OT)

  • In-Home Intensive ABA/IBI Therapy
  • Half & Full-Day Intensive program in Clinic
  • Social Skills Groups
  • Parent and School Training

What you need to Prepare if Interested in Services at Simone Friedman SLS

  1. Gather any relevant diagnostic documents regarding your child.
  2. Check your schedules
  3. Look into funding options (personal, extended health care benefits, DFO funding &/or charitable grants).

*visit our site for charitable grants info

Take Action
Call our office at 416-546-3044 or email us at to book an appointment for an assessment. Our admin team will use your prepared info to help you through the process.

What to Expect

  1. All new clients with ASD begin here with a comprehensive ESDM assessment completed by both our Speech-Language Pathologist and Occupational Therapist.
  2. An individualized treatment program is created based on your goals as well as the assessment findings.
  3. Recommendations are made for type, length and frequency of treatment.
  4. If TPAS approved and DFO funded, our DFO approved consulting psychologist will oversee the IBI program.
  5. Treatment commences and a copy of the weekly goals are provided to the parent for personal records and for generalization at home.

Learn More About Our Services

Evidence to Support Early Intervention

Evidence to Support Early Start Denver Model

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Adolescents and Adults with Autism

Transitions at each stage of life present challenges for everyone, but adolescents and young adults with autism need additional support to cope with new social, educational and vocational demands.

Social Communication:
Adolescents and young adults with Autism are presented with many challenges related to socialization. Interpreting non-verbal (e.g., facial expressions, body language) and higher level language (e.g., sarcasm) can be very challenging. Learning how to use one’s Executive Functions to mitigate emotions using verbal problem solving is another difficulty. Understanding the purposes of communication (e.g., to: discover, relate, help, persuade, play, control) and problems that can present (e.g., eye contact, turn-taking, initiation of conversation, perseveration, tangential, facial expression etc) are important skills when navigating the following situations:

  1. Social-communication between friends
  2. Social-emotional understanding – theory of mind and egocentric thought
  3. Development of new relationships
  4. Maintenance of relationships
  5. Breakdowns in relationships
  6. Bullying
  7. Sexual/Romantic relationships

Educational Demands:
Transitioning from adolescents to young adulthood can be challenging. The supported/protected environment provided within an IEP while transitioning from Primary through to high-school may not follow when transitioning to College and/or University. It is important to determine the individuals educational profile (i.e., strengths and weaknesses) in order to provide recommendations for direction. Once an assessment has been completed, accommodations can be put in place and tools can be ordered to compensate for weaknesses. The following areas should be addressed when making decisions around tertiary education:

  1. Speech-Language Pathology Evaluation to determine strengths and weaknesses in: Receptive & Expressive Language, Social-Communication, Reading, Writing, Auditory Processing, Attention, Executive Functions, Verbal Memory, Verbal Problem-Solving.
  2. Activity of Daily Living Assessment by an Occupational Therapist to determine strengths and weaknesses in: Independent Living Skills (e.g, budgeting, hygiene, cooking, dressing, laundry etc).
  3. Accommodations that need to be put in place
  4. Tools required to compensate for any weakness.

Vocational Readiness:
Entering the Vocational world for an adult with Autism can be very daunting and exciting. In order to allow for a smooth and successful transition, the following areas should be addressed:

  1. Vocational “fit” testing
  2. Job Searching Skills
  3. Resume building and writing
  4. Cover letter writing
  5. Interview skills and training
  6. Training in interpersonal communication between colleagues and employee/employer relationship
  7. Training in job skills
  8. On the Job Coaching provided in the workplace to ensure generalization of job skills
  9. Support and education provided to the employer