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.
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.
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.
Sensory differences present differently across individuals and sensory systems. Common signs include:
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.
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.
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.
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.
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 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.
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.
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Verified Facts
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 concludes early intensive behavioural intervention (EIBI) produces moderate-to-large positive effects on adaptive behaviour and communication for young children with ASD
WHO recommends accessible, community-based early interventions for children with autism — timely evidence-based psychosocial interventions improve communication and social engagement
87,692 — children are registered in the Ontario Autism Program
23.1% — 23,875 children enrolled in Core Clinical Services; 20,293 have active funding agreements ()
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