Studies consistently find that a large majority of autistic people experience sensory processing differences. Learn what SPD is, how it affects daily life, and what supports are available in Ontario.
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Sensory Processing Disorder: Understanding SPD in Autism Sensory processing differences can also occur without autism. Sensory differences can affect daily life for autistic people. Sensory differences present differently across individuals and sensory systems. A registered occupational therapist can assess sensory processing. Read the guide www.endthewaitontario.com/sensory-processing-disorder
Download English captions (WebVTT)Sensory processing differences can also occur without autism. A short explainer with music and captions. 33 seconds. Watch it full screen · See all short explainers
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American Psychiatric Association, Autism Spectrum Disorder · Verified 2026-11-03
General information only, not a diagnosis, treatment plan, crisis service, or individual estimate. Confirm your next step with the linked source or a qualified professional.
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.
Sensory reactivity is included in the DSM-5 diagnostic criteria for autism. 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 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.
Sensory differences present differently across individuals and sensory systems. The same person may be hypersensitive in some areas and hyposensitive in others.
| Sensory domain | Hypersensitive | Hyposensitive | Source |
|---|---|---|---|
| Auditory | Distress at vacuum cleaners, crowd noise, hand dryers, or sudden loud sounds | Not noticing when spoken to, preference for very loud music | American Psychiatric Association |
| Tactile | Aversion to certain fabric textures, clothing tags, or light touch | High pain tolerance, not noticing temperature extremes, seeking deep pressure | American Psychiatric Association |
| Visual | Difficulty with flickering lights, bright environments, or complex visual patterns | Seeking visual input, watching spinning objects, flickering lights | American Psychiatric Association |
| Proprioceptive | Discomfort with physical activity or resistance | Crashing into furniture, heavy lifting, seeking tight hugs or weighted blankets | American Psychiatric Association |
| Vestibular | Motion sickness, fear of heights or movement, avoiding swings or escalators | Strong craving for spinning, swinging, and rocking | American Psychiatric Association |
| Olfactory / Gustatory | Strong reactions to food textures, cooking smells, or perfumes | Seeking strong flavors, not noticing household odors | American Psychiatric Association |
What official government data tracks the Ontario autism waitlist?
The current province-wide waitlist record is the MCCSS FOI data published through the Ontario Autism Coalition data hub. As of May 2026, it shows 91,974 registered children and 22.5% with active funding agreements. Historical FAO, Auditor General, OHRC, and AccessOAP records provide separate context and should be cited for their own claims.
Source: MCCSS FOI via OAC May 2026 · Open source record
What does the WHO say about early autism intervention timing?
The WHO Fact Sheet on Autism Spectrum Disorders (updated Sept. 17, 2025) 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 (updated Sept. 17, 2025); Dawson et al., Pediatrics 2010 (PMID 19948568) · Open source record
Occupational therapy using Ayres Sensory Integration is the most studied approach. Its evidence is still emerging. 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.
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.
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.
A meltdown or shutdown is a nervous system response to sensory overload, not defiance or a behavioural choice. During a meltdown or shutdown, the priority is safety and reducing input, not correction or discipline. Move to a quieter, dimmer space if possible, reduce demands and language, and give the person time to recover without an audience.
Seek urgent medical or mental health support if sensory distress is accompanied by self-injury, a risk of harm to others, or signs of a medical emergency (such as a head injury from crashing behaviour). This page provides general education only, it does not replace an individualized safety plan from a treating clinician, and it cannot assess any specific child or adult.
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.
Sensory reactivity is included in the DSM-5 diagnostic criteria for autism spectrum disorder. Sensory processing differences can also occur without autism.
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.
Occupational therapy using Ayres Sensory Integration is the most studied approach. Its evidence is still emerging (see our SI therapy guide). Trained OTs use structured sensory activities to support participation in daily life. Environmental changes such as noise-reducing headphones or dimmed lighting may help some people.
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 OAP Core Clinical Services funding. School boards also provide some OT assessment through the IPRC process for children with identified exceptionalities.
Families navigating autism services in Ontario face a documented multi-year wait. Here is the Ontario data — and a two-minute way to push back, when you are ready.
Sources on this page
Key claims are paired with their source, evidence tier, and verification date so readers can inspect the public record directly.
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
Check the author’s context, review method, and how to report an error.
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Lived experience: Parent of autistic child in the OAP system