Sensory Processing Disorder: Understanding SPD in Autism

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.

Getting Assessed: What to Expect

SPD is not a stand-alone diagnostic code, so assessment usually happens through an occupational therapist rather than a physician. A referral can come from a pediatrician, family doctor, or be made directly to a private OT clinic in most of Ontario, no physician referral is legally required to see a private OT. The assessment typically combines a parent/caregiver interview, standardized sensory questionnaires (such as the Sensory Profile), and structured observation of the child engaging in play and movement tasks.

An OT assessment does not diagnose autism, only a qualified diagnostic clinician (a developmental pediatrician, psychologist, or psychiatrist) can do that. What an OT assessment produces is a sensory profile: a picture of which systems are over- or under-responsive, and a starting point for therapy goals and accommodation recommendations. Waits for private OT assessment vary by clinic; publicly funded OT through school boards is typically limited to consultation rather than a full sensory work-up.

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.

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