Sensory Processing Disorder: Signs, Types and How OT Helps
Sensory processing disorder explained by an occupational therapist: the signs by age, the main types, SPD vs autism and ADHD, assessment and treatment.
What is sensory processing disorder?
Every second, our brain receives information from our senses: touch, movement, body position, sight, sound, taste, smell, and signals from inside the body. Most of us filter and organise this information without thinking. We ignore the feel of our socks, notice when someone calls our name, and keep our balance on a moving bus.
Sensory processing disorder (SPD), previously called sensory integration dysfunction, occurs when the brain is unable to process this sensory information efficiently. It can happen when the brain does not receive the input, when the input it receives is inconsistent, or when the input is consistent but does not integrate properly. The result is a response that is too big, too small, or poorly organised for the situation.
A child with SPD receives the same sensations from the environment as other children, but they are unable to process them, so they give no response or a different response. Their behaviour is often misread as naughtiness, fussiness or not listening.
To understand the normal process first, read our guide to sensory integration.
The three main types of SPD
Researchers (Miller et al., 2007) group sensory processing difficulties into three patterns. A child can show more than one.
| Pattern | Subtype | What you might see |
|---|---|---|
| Sensory modulation disorder | Over-responsivity | Reacts too strongly: covers ears at hand dryers, refuses certain clothes, hates having hair washed |
| Under-responsivity | Reacts too little: doesn't notice being called, seems tired or slow to start, misses that their face is dirty | |
| Sensory craving or seeking | Wants more and more: crashes into furniture, spins, touches everything, chews non-food items | |
| Sensory discrimination disorder | Any sense | Struggles to tell sensations apart: can't find a coin in a pocket without looking, misjudges distances, confuses similar sounds |
| Sensory-based motor disorder | Postural disorder | Poor balance and core stability: slumps in a chair, tires quickly, falls easily |
| Dyspraxia | Trouble planning and sequencing new movements: slow to learn to ride a bike, dress or use playground equipment |
Based on Miller LJ et al. (2007), a proposed nosology for sensory processing disorder.
Another way to see it: Dunn’s four sensory patterns
Occupational therapist Winnie Dunn describes sensory processing by two questions: how much input does it take for this person to notice (threshold), and do they act to get more or less of it (self-regulation)? Everyone fits somewhere on this model; it only becomes a problem when a pattern is extreme.
Threshold
Bystander (low registration)
Misses cues others notice. May seem quiet, slow to respond or 'in their own world'.
Seeker
Actively hunts for more input: moving, touching, making noise. Enjoys busy places.
Sensor (sensitivity)
Notices everything and is easily distracted or bothered, but puts up with it.
Avoider
Notices a lot and acts to limit it: leaves the room, avoids crowds, sticks to routines.
Self-regulation
Based on Dunn (1997). The Sensory Profile 2 questionnaire scores children on these four patterns.
Signs of sensory processing disorder by age
Sensory processing disorder’s symptoms vary from person to person. These are common examples; one or two on their own are not a concern. What matters is a pattern that persists and disrupts daily life.
| Age | Common signs |
|---|---|
| Babies and toddlers | Very hard to settle or extremely sleepy; strong dislike of baths, nappy changes or being held; feeding difficulties with new textures; delayed crawling or walking; little reaction to sounds or faces |
| Preschool | Meltdowns in noisy or busy places; refuses messy play; picky eating because of texture; constant crashing, jumping or spinning; fear of swings and slides; clumsy and slow to dress |
| School age | Bothered by clothing tags and seams; covers ears at school assemblies; can't sit still or slumps at the desk; poor handwriting and pressure on the pencil; trouble with PE, catching and riding a bike; avoids friends' parties |
| Teens and adults | Avoids crowds, bright lights or strong smells; seeks intense activities; easily overwhelmed and tired at the end of the day; difficulty with new physical tasks such as driving |
Over-responsive, under-responsive or seeking?
You can usually see which way a child’s system leans by watching how they react to the same everyday situation.
| Situation | Over-responsive child | Under-responsive or seeking child |
|---|---|---|
| Getting dressed | Complains about tags, seams and socks; wants the same soft clothes | Doesn't notice clothes are twisted or wet; may strip off clothes to feel more |
| Bath and hair care | Screams at hair washing, cutting or brushing | Splashes hard, wants very hot or cold water, or doesn't seem to notice the temperature |
| Playground | Afraid of swings, slides and heights | Climbs high without fear, spins for long periods without getting dizzy |
| Mealtimes | Gags on lumpy or mixed textures | Stuffs the mouth, prefers very crunchy or spicy food, chews shirt collars |
| Noise | Covers ears; melts down at birthday parties | Doesn't respond to their name; makes lots of noise themselves |
SPD, autism and ADHD: how they differ
Sensory processing difficulties may coexist with ADHD, autism, cerebral palsy, Down syndrome, developmental coordination disorder and anxiety. Because they overlap so much, a careful assessment matters.
| Sensory processing difficulties | Autism | ADHD | |
|---|---|---|---|
| Core feature | Unusual responses to sensory input | Differences in social communication plus restricted, repetitive behaviours | Inattention and/or hyperactivity and impulsivity |
| Sensory differences | Always | Very common (part of the diagnostic criteria) | Common, especially sensory seeking |
| Social communication | Usually typical, but may avoid busy social settings | Different from peers | Usually typical; may interrupt or miss social cues when distracted |
| Formal diagnosis | Not in DSM-5; recognised in DC:0–5 for young children | DSM-5 diagnosis | DSM-5 diagnosis |
| Main help | Occupational therapy | A team approach, often including speech therapy, OT and education support | Behavioural strategies, education support, medication for some, OT for daily skills |
What causes sensory processing difficulties?
The exact causes are still being studied. Research points to a mix of factors:
- Genetics: sensory differences often run in families.
- Prematurity and low birth weight: babies born early have higher rates of sensory processing difficulties.
- Early experiences: long hospital stays or limited opportunity to move and play in infancy.
- Brain differences: studies in children with sensory over-responsivity have found differences in how the brain processes and connects sensory information.
Sensory processing difficulties are nobody’s fault, and they are not caused by parenting.
How occupational therapists assess SPD
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Parent and teacher questionnaires
Such as the Sensory Profile 2 or the Sensory Processing Measure (SPM-2).
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Observation
Watching the child play, move, eat and handle textures, at the clinic and sometimes at school.
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Standardised testing
Tests of balance, coordination, motor planning and sensory discrimination, such as the EASI or BOT-2.
-
Goals together
Agreeing which daily activities matter most: dressing, eating, sleep, school, play.
How occupational therapy helps
When sensory processing difficulties get in a child’s way, sensory integration-based occupational therapy is often recommended. Help usually combines four things:
- Sensory integration therapy: play-based sessions with swings, ramps, textures and heavy work that give the “just-right challenge”.
- A sensory diet: a planned schedule of sensory activities through the day, such as heavy work before homework or calming deep pressure at bedtime.
- Changes to the environment: noise-reducing headphones, a quiet corner, seamless socks, a movement break plan at school.
- Coaching for parents and teachers: understanding the child’s sensory profile, so behaviour is seen in a new light and supported instead of punished.
Activity ideas for each sense: tactile, vestibular and proprioceptive.
Sensory processing in adults
Sensory differences don’t always go away. Many adults describe lifelong sensitivity to noise, light, touch or smell, or a strong need for movement. Understanding your own sensory profile helps you plan: choosing quieter workspaces, building movement into the day, or using noise-cancelling headphones. Occupational therapists also use sensory strategies in mental health settings; see OT in mental health.
Related guides: Sensory overload, Sensory seeking behavior, Interoception, Sensory toys, Heavy work activities.
References
- Miller LJ, Anzalone ME, Lane SJ, Cermak SA, Osten ET. Concept evolution in sensory integration: a proposed nosology for diagnosis. American Journal of Occupational Therapy. 2007;61(2):135–140.
- Dunn W. The impact of sensory processing abilities on the daily lives of young children and their families: a conceptual model. Infants and Young Children. 1997;9(4):23–35.
- Ahn RR, Miller LJ, Milberger S, McIntosh DN. Prevalence of parents’ perceptions of sensory processing disorders among kindergarten children. American Journal of Occupational Therapy. 2004;58(3):287–293.
- Ben-Sasson A, Carter AS, Briggs-Gowan MJ. Sensory over-responsivity in elementary school: prevalence and social-emotional correlates. Journal of Abnormal Child Psychology. 2009;37(5):705–716.
- ZERO TO THREE. DC:0–5 Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood. 2016.
- American Academy of Pediatrics. Sensory integration therapies for children with developmental and behavioral disorders. Pediatrics. 2012;129(6):1186–1189.
- Kranowitz CS. The Out-of-Sync Child: Recognizing and Coping with Sensory Processing Disorder. Penguin; 2005.
Frequently asked questions
What is sensory processing disorder?
What are the signs of sensory processing disorder in a child?
Is sensory processing disorder a form of autism?
Can a child grow out of sensory processing disorder?
How is sensory processing disorder diagnosed?
What is the treatment for sensory processing disorder?
Written by
Deepam Pawar, OT
Deepam Pawar is an occupational therapist and co-founder of Occupational Therapy OT. He focuses on clinical frameworks, assessment, and evidence-based practice.
All articles by Deepam →This article is for general education and is not a substitute for individualized assessment or treatment by a licensed occupational therapist. Always seek the guidance of a qualified professional for specific concerns.
