How do ABA therapy and ESDM differ when started in infancy for autism? 

The NHS describes early support for autistic children in terms of play, communication and everyday life, rather than specific branded therapies. In the same way, NICE focuses on social-communication, developmental and parent-mediated interventions, and does not endorse Applied Behaviour Analysis (ABA), Early Intensive Behavioural Intervention (EIBI) or the Early Start Denver Model (ESDM) by name, even when support begins in infancy. 

Understanding the concept 

ABA is a behaviour-analytic framework that teaches skills step by step. Early intensive ABA, often called EIBI, usually involves breaking communication, play and self-care into small targets, using prompts and reinforcement to help a child learn. Classic programmes in the research literature can reach 20 to 40 hours a week of one-to-one teaching, started around age two or three, sometimes a little earlier.  

A study in PubMed revealed that ESDM is different in feel, even though it also uses behaviour-analytic tools. It is a naturalistic developmental behavioural intervention that blends ABA principles with developmental and relationship goals. Sessions are play based, follow the child’s interests and focus on shared attention, imitation, joint play and functional communication. Parents are coached to use ESDM strategies in daily routines, so a significant proportion of the intervention happens in natural family life rather than only in therapy rooms. 

The NHS and NICE both emphasise that support should be family-centred, play-based and tailored to the child, rather than driven by a specific programme brand. 

Evidence and impact 

The best-known ESDM trial in toddlers is Dawson and colleagues’ randomised controlled trial, which enrolled children aged 18 to 30 months. Children were allocated either to two years of intensive ESDM, about 20 hours a week delivered by therapists and parents, or to community treatment as usual. Community care often included speech and language therapy and some behavioural work but at lower intensity and without a unified model. After two years, the ESDM group showed larger gains in IQ, language and adaptive behaviour, and were more likely to move from an autism diagnosis to a broader developmental diagnosis. Parents also reported meaningful everyday improvements. 

More recent work has adapted ESDM for even younger infants at high likelihood of autism, such as siblings of autistic children. Parent-mediated ESDM trials starting between about 7 and 24 months show that coaching parents to use ESDM strategies can improve parent responsiveness and early social-communication and can reduce the emergence of some autistic characteristics, although these studies are typically small and heterogeneous. 

For ABA and EIBI, evidence for very early starts often sits inside broader preschool samples. A meta-analysis of early intensive behavioural intervention reported that programmes started before age four, typically around two to three years, are associated with improvements in IQ and adaptive behaviour compared with eclectic services. The NIHR evidence synthesis reached similar conclusions, but highlighted that most studies were non-randomised and that data specifically for infants under two were very limited.5 

A wider meta-analysis of early childhood autism interventions in the BMJ suggests that naturalistic developmental behavioural interventions, including ESDM, have particularly strong evidence for improving core social-communication difficulties, while behavioural programmes more broadly show benefits for challenging behaviour and some social-emotional outcomes. However, this analysis still includes mostly children aged two to six rather than tiny infants. 

There is currently no robust randomised trial directly comparing a full EIBI programme with ESDM started in infancy. 

Practical support and approaches 

In real life, families in the UK are directed by the NHS towards early help through health visitors, GPs and community child-development teams rather than towards a specific brand. Typical early support looks like: 

• advice on play, routines and sleep 

• support for communication from speech and language therapists 

• help from occupational therapists with sensory and motor needs 

• parenting and relationship-based programmes that enhance interaction 

The NHS encourages families to learn about autism, link with local services and ask about parent programmes or therapies that fit their circumstances, without naming ABA or ESDM. 

Where ESDM or ABA-informed approaches are available, they are often blended with wider developmental input. ESDM tends to be delivered at moderate intensity with substantial parent coaching. ABA-informed early programmes may still be more therapist led, although many now offer parent training too. For infants and very young toddlers, parent-mediated, play-based models usually fit better with everyday life than highly clinic-based schedules. 

Challenges and considerations 

Both ABA and ESDM literatures have important limitations, especially in infancy. 

For ABA and EIBI, the surveillance report notes that many studies are small, non-randomised and conducted in specialist centres, which makes it hard to generalise findings to typical UK services. Outcomes also tend to emphasise IQ and adaptive scores rather than lived experience, wellbeing, or family stress. 

For ESDM, the key toddler trial and several follow-up studies are stronger methodologically but still involve modest sample sizes and may not capture long-term outcomes into later childhood. Parent-mediated ESDM study in at-risk infants show promising changes in social-communication, but numbers are small and there is relatively little data beyond the preschool years. 

Both fields have gaps in monitoring adverse effects or unintended consequences. Autistic-led perspectives highlight that early intervention should not aim to suppress harmless autistic behaviours or train children simply to appear more “typical”, which echoes National Autistic Society (NAS) guidance on avoiding coercive methods. 

How services can help 

Within the UK, early pathways are framed around principles rather than programme logos. NICE recommends specific social-communication interventions that use play-based strategies with parents and teachers to increase joint attention, engagement and reciprocal communication, especially in preschool children. It also recommends multidisciplinary input, including speech and language therapy and occupational therapy where needed. 

The NHS highlights support for families themselves, including parenting help, mental-health support and local groups. NAS provides information on communication-focused interventions and encourages families to ask about goals, evidence and how each approach respects autistic communication and identity. 

When considering ABA-informed approaches or ESDM-style NDBIs in infancy, helpful questions include: 

• How are parents involved and coached? 

• What outcomes are being prioritised, for example shared joy, communication, daily life, rather than only test scores? 

• How are sensory needs, regulation and the child’s comfort taken into account? 

Takeaway 

Starting structured support in infancy can help autistic children and those at high likelihood for autism build communication and participation skills. ESDM has relatively strong trial evidence in toddlers, and early intensive ABA has meta-analytic support for cognitive and adaptive gains when started before age three, but both literatures are methodologically mixed and there are no direct head-to-head infant trials. In line with NHS and NICE, the most important questions are whether an approach is family-centred, play-based, respectful of autistic strengths and grounded in good evidence, rather than whether it carries an ABA or ESDM label. 

If you or someone you support would benefit from early identification or structured autism guidance, visit Autism Detect, a UK-based platform offering professional assessment tools and evidence-informed support for autistic individuals and families.