What studies compare ABA therapy with occupational therapy outcomes in autism? 

The NHS describes support for autistic children in terms of communication, daily living and participation, rather than any single “best” therapy. Similarly, NICE recommends developmental, behavioural and functional support but does not endorse brand-name programmes such as ABA, EIBI or Ayres Sensory Integration (ASI). That makes the question of how Applied Behaviour Analysis (ABA) compares with occupational therapy (OT) an important but still emerging evidence area. 

Understanding the concept 

ABA is a behaviour based framework that breaks skills into small steps and teaches them using structured practice, prompting and reinforcement. Meta analysis of ABA and early intensive behavioural intervention tend to focus on outcomes like IQ, adaptive behaviour, specific communication skills and sometimes autism symptom scores, often in high-intensity programmes over many hours per week. Reviews summarised in recent scoping work in PubMed show medium to large gains versus eclectic comparison services, but with generally low to moderate evidence quality and heterogeneous study designs. 

OT, including ASI, starts from a different framework. Children’s OT services within the NHS describe their role as helping children participate in everyday activities like dressing, play and school tasks by addressing physical, sensory and cognitive barriers and adapting environments and routines. ASI is a specific OT approach that focuses on sensory processing differences and their impact on regulation and participation. 

Evidence and impact 

Direct head-to-head research comparing ABA and OT is very limited. A recent randomised trial by Schaaf and colleagues is the first to directly compare manualised OT using ASI with ABA and a no-treatment group in autistic children with sensory processing differences. Children were randomised to OT-ASI, ABA or no treatment, with around 30 one-hour sessions in the active arms. Both OT-ASI and ABA outperformed no treatment on some functional measures of daily living skills and individualised goals, with OT-ASI showing stronger effects in sensory-linked participation and ABA in some task specific behaviours, according to the abstract. Full data are still emerging and this study has not yet fed into NICE surveillance. 

Evidence for OT-based sensory interventions more broadly comes from systematic reviews and early trials of Ayres Sensory Integration (ASI). A review by Sarah A. Schoen and colleagues (2018) in PubMed concluded that ASI shows strong evidence for improving individually defined functional goals and moderate evidence for enhancing self-care and reducing caregiver support needs in children with autism though the overall evidence base remains relatively small and focused on short-term outcomes. 

In contrast, the NIHR synthesis of early intensive ABA based interventions found moderate improvements in IQ and adaptive behaviour compared with eclectic community services that usually included OT, speech and language therapy and educational support. However, underlying studies were often small, non-randomised and methodologically variable, making it impossible to isolate the specific contribution of ABA versus OT within these mixed packages. 

Overall, the evidence suggests ABA and OT can both improve certain outcomes, but they have been studied with different targets and designs, which makes direct comparison difficult. 

Practical support and approaches 

In everyday practice, families rarely choose between “pure” ABA or “pure” OT. The NHS focuses on helping children manage daily life through simple language, visual supports, routines and reasonable adjustments, alongside therapies such as speech and language therapy and OT where needed. NICE recommends social communication interventions and access to OT for children who struggle with self-care or motor skills, within a multidisciplinary team. 

The National Autistic Society highlights that no single intervention is right for everyone and that support should be person centred, non-coercive and focused on meaningful goals. 

Challenges and considerations 

There are several key limitations to keep in mind: 

• High-quality direct ABA versus OT comparisons are almost non-existent, with one emerging trial in OT-ASI versus ABA and no long-term follow up yet. 

• ABA evidence is larger in volume but often methodologically weak and usually compares ABA to eclectic services that include OT, rather than to clearly defined OT interventions. 

• OT evidence for ASI and sensory approaches is smaller and newer, and has not led NICE to recommend sensory integration as a stand-alone autism treatment. 

Across both fields, there is limited data on long-term quality of life, autistic identity, self advocacy and family wellbeing. 

How services can help 

In the UK, support is guided by NICE and NHS frameworks rather than by choosing one branded therapy. OT and behavioural input are often combined within a multidisciplinary plan that aims to improve participation, independence and emotional regulation. Local services may offer OT for sensory and functional needs alongside PBS informed behavioural advice, speech and language therapy and school-based support. 

Takeaway 

Current research comparing ABA and OT in autism is sparse and largely indirect. ABA studies tend to show gains in cognitive and adaptive scores compared with eclectic services that often include OT, while OT and ASI studies suggest improvements in participation and daily living skills for children with sensory differences. In line with NHS and NICE, it is more helpful to focus on whether a child’s support plan is functional, collaborative and centred on meaningful goals than on whether it carries an ABA or OT 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.