Sensory Processing Disorder: Understanding SPD in Autism
Up to 90% of autistic people experience sensory processing differences. Learn what SPD is, how it affects daily life, and what supports are available in Ontario.
TL;DR
Up to 90% of autistic people experience sensory processing differences
SPD is not a standalone DSM-5 diagnosis but is recognized as a co-occurring feature
Occupational therapists (OTs) are the primary providers of sensory-focused therapy
Sensory accommodations at home, school, and work can significantly reduce sensory stress
Who this affects
These challenges are common among the children waiting for services.
Ontario Autism Program key statistics (CBC FOI Jan 2026, verified 2026-04-29)
Metric
Value
Children registered
88,175
Have active funding
20,666
Still waiting
67,509
What Is Sensory Processing Disorder?
Sensory Processing Disorder (SPD) describes a pattern of difficulties in how the brain organizes and responds to sensory input from the body and the surrounding environment. Sensory input includes not just the five traditional senses — sight, hearing, touch, smell, and taste — but also proprioception (body position and movement) and vestibular input (balance and spatial orientation).
People with SPD may be hypersensitive (over-responsive) or hyposensitive (under-responsive) to sensory stimuli, or may show a mixed pattern across different sensory domains. SPD is not a standalone diagnosis in the DSM-5, but sensory reactivity is explicitly included in the autism spectrum disorder diagnostic criteria. Occupational therapist A. Jean Ayres first described sensory integration dysfunction in the 1960s and 1970s, and research in this area has expanded significantly since.
The Connection to Autism
Research consistently shows that sensory processing differences are among the most common features of autism. Estimates suggest that 69–90% of autistic individuals experience atypical sensory reactivity. For the DSM-5 revision in 2013, hyper- or hyporeactivity to sensory input was added as a core feature within the restricted, repetitive behaviors diagnostic criterion.
Sensory differences can profoundly affect daily life for autistic people. Loud environments, fluorescent lighting, certain food textures, and unexpected physical contact can trigger significant distress, sometimes escalating to meltdowns or shutdowns. Environments designed without sensory considerations — including many schools and workplaces — create unnecessary barriers for autistic people.
Signs and Types of Sensory Differences
Sensory differences present differently across individuals and sensory systems. The same person may be hypersensitive in some areas and hyposensitive in others.
Auditory
Hypersensitive
Distress at vacuum cleaners, crowd noise, hand dryers, or sudden loud sounds
Hyposensitive
Not noticing when spoken to, preference for very loud music
Tactile
Hypersensitive
Aversion to certain fabric textures, clothing tags, or light touch
Hyposensitive
High pain tolerance, not noticing temperature extremes, seeking deep pressure
Visual
Hypersensitive
Difficulty with flickering lights, bright environments, or complex visual patterns
Crashing into furniture, heavy lifting, seeking tight hugs or weighted blankets
Vestibular
Hypersensitive
Motion sickness, fear of heights or movement, avoiding swings or escalators
Hyposensitive
Strong craving for spinning, swinging, and rocking
Olfactory / Gustatory
Hypersensitive
Strong reactions to food textures, cooking smells, or perfumes
Hyposensitive
Seeking strong flavors, not noticing household odors
Treatment and Support Strategies
Occupational therapy with a sensory integration (SI) approach is the primary evidence-based intervention for SPD. Trained OTs use structured, child-directed activities to challenge the nervous system in a controlled way — swings, obstacle courses, tactile bins, and proprioceptive exercises. The goal is to support the brain in processing sensory input more adaptively. Learn more about sensory integration therapy.
Environmental accommodations are equally important. Sensory accommodations do not require a clinical setting — they can be implemented at home, in school, and at work. Examples include noise-cancelling headphones, sensory corners with low lighting, fidget tools, flexible seating, and clothing from low-sensory fabric brands. A sensory diet — a schedule of targeted sensory activities throughout the day — can also help regulate the nervous system proactively.
What Is a Sensory Diet?
A sensory diet is not a food diet — it is a personalized schedule of sensory activities designed by an occupational therapist to help regulate the nervous system throughout the day. Activities might include swinging before school, fidget tools during class, heavy work activities (carrying books, pushing a cart) between transitions, and quiet time with a weighted blanket after school. The goal is proactive regulation, not reactive management of overload.
Sensory Accommodations at Home and School
Families and educators can reduce sensory stress through practical accommodations that cost little or nothing. At home: establish predictable routines, allow sensory tools at mealtimes, offer choices about clothing, and create a low-stimulation quiet space. At school: request sensory accommodations through the IEP or Individual Education Plan, advocate for sensory breaks, fidget tools, alternative seating, and access to quieter learning environments.
In Ontario, children with autism who are enrolled in school have the right to an IEP. Sensory needs can and should be documented in the IEP with specific accommodations. Families experiencing challenges with school accommodations can request an IPRC (Identification, Placement, and Review Committee) meeting. Learn more about autism supports in Ontario schools.
Frequently Asked Questions
What is sensory processing disorder?
Sensory Processing Disorder (SPD) refers to difficulties in how the brain organizes and responds to sensory information from the body and environment. People with SPD may be oversensitive (hypersensitive) or undersensitive (hyposensitive) to sensory input — including touch, sound, light, smell, taste, movement, and body position.
How does sensory processing disorder relate to autism?
Research consistently finds that up to 90% of autistic people experience some degree of sensory processing differences. Sensory reactivity is included in the DSM-5 diagnostic criteria for autism spectrum disorder. While SPD can occur without autism, it is extremely common among autistic individuals and often significantly impacts daily functioning.
What are the signs of sensory processing difficulties?
Signs vary by sensory domain and direction of sensitivity. Hypersensitivity signs include distress at loud sounds, aversion to certain textures or fabrics, difficulty in bright or flickering light, and strong reactions to smells. Hyposensitivity signs include seeking intense sensory input (crashing into things, high pain tolerance), difficulty feeling temperature, or not noticing when clothing is uncomfortable.
What treatments help sensory processing disorder?
Occupational therapy with a sensory integration (SI) approach is the primary evidence-based treatment for SPD. Trained OTs use structured sensory activities — swings, weighted tools, tactile and proprioceptive exercises — to support nervous system regulation. Environmental accommodations (noise-cancelling headphones, sensory-friendly classrooms, dimmed lighting) are also highly effective.
How do I get my child assessed for SPD in Ontario?
A registered occupational therapist can assess sensory processing. Referrals can be made by a pediatrician, family doctor, or obtained directly from a private OT clinic. Children with an autism diagnosis may be eligible for OT through the OAP Childhood Budget. School boards also provide some OT assessment through the IPRC process for children with identified exceptionalities.
What official government data tracks the Ontario autism waitlist?
Primary sources include: Financial Accountability Office (FAO) annual reports, Ontario Auditor General reviews, OHRC policy statements, publicly available FOI data, and AccessOAP program data. Latest FOI data (Dec 2025) shows 88,175 registered children with only 23.4% having active funding agreements (up from 70,176 registered in the FAO 2023-24 report).
Source: FAO, Auditor General, OHRC, CBC FOI Jan 2026
What does the WHO say about early autism intervention timing?
The WHO Fact Sheet on Autism Spectrum Disorders (2023) states that timely access to early evidence-based psychosocial interventions can improve the ability of autistic children to communicate effectively and interact socially. Dawson et al. (2010, Pediatrics; PMID 19948568) confirmed in an RCT that ESDM (Early Start Denver Model) at 18–30 months produced significant developmental gains.
Source: WHO Fact Sheet: Autism Spectrum Disorders (2023); Dawson et al., Pediatrics 2010 (PMID 19948568)
About This Article
Written by:Spencer Carroll - Founder & Autism AdvocateParent of autistic child navigating OAP system
Early Start Denver Model (ESDM) delivered to children aged 18–30 months produced significant gains in IQ, adaptive behaviour, and autism severity — some children no longer met diagnostic criteria at follow-up
Cochrane systematic review finds evidence that early intensive behavioural intervention (EIBI) may produce positive effects on adaptive behaviour and communication for young children with ASD (low certainty of evidence)
WHO recommends accessible, community-based early interventions for children with autism — timely evidence-based psychosocial interventions improve communication and social engagement