Sensory processing disorder (SPD) is a term used to describe a pattern of sensory processing difficulties that significantly affect a person's daily functioning, when those difficulties are not better explained by another condition such as autism or ADHD. It is not currently a standalone diagnosis in the DSM-5 or ICD-11, but it is widely used by occupational therapists and increasingly recognised in clinical practice.
Key Takeaways
- SPD involves difficulties in receiving, organising, and responding to sensory information
- Both hypersensitivity (over-responding) and hyposensitivity (under-responding) are features of SPD
- SPD frequently co-occurs with ADHD, autism, and anxiety
- Occupational therapy is the primary treatment — a "sensory diet" of tailored activities
- A chew necklace can be part of a sensory diet for children with oral sensory seeking
- Not a formal DSM/ICD diagnosis, but clinically valid and well-recognised
What Is Sensory Processing Disorder?
Sensory processing disorder — also called sensory integration dysfunction — is a condition in which the brain has difficulty receiving, processing, and responding to information from the senses in a typical, appropriate way. A child with SPD may be overwhelmed by sounds that others barely notice, may seek intense physical stimulation that others find excessive, or may struggle to coordinate their body in tasks that peers find simple.
SPD was first described and studied systematically by Dr Jean Ayres (see: sensory integration theory) in the 1970s. Research since then has identified it as a distinct pattern of neurological functioning, though there is still debate about its status as a standalone diagnosis versus a feature of other conditions.
Types of SPD
Researchers have identified several subtypes of SPD based on the pattern of difficulties:
Sensory Modulation Disorder
Difficulty regulating the intensity of response to sensory input. Subtypes:
- Sensory over-responsivity (hypersensitivity): over-reacting to ordinary sensory input — distress from noise, texture, light touch, or smell
- Sensory under-responsivity (hyposensitivity): not noticing or reacting to input that others would find obvious — may seem "in a world of their own"
- Sensory seeking/craving: actively seeking intense sensory input — crashing, spinning, chewing hard, touching everything. This is the profile most associated with chew necklace use
Sensory Discrimination Disorder
Difficulty distinguishing between different sensory signals — for example, not being able to identify what is touching the skin without looking, or having difficulty telling similar sounds apart.
Sensory-Based Motor Disorder
Motor planning difficulties (dyspraxia) and postural control problems driven by poor proprioceptive and vestibular processing.
How SPD Affects Daily Life
The impact of SPD depends on which sensory channels are affected and in which direction. Common challenges include:
- Refusing to wear certain clothing because textures feel unbearable
- Meltdowns in busy, noisy environments (supermarkets, school corridors)
- Extreme difficulty sitting still for classroom activities
- Putting everything in the mouth — seeking oral proprioceptive input
- Crashing into walls, furniture, and people — seeking deep pressure
- Difficulty with balance and coordination
- Very restricted diet due to texture sensitivities
How Occupational Therapy Helps
Paediatric occupational therapy for SPD involves:
- Assessment: standardised tools such as the Sensory Profile or the Sensory Processing Measure identify the pattern of sensory differences
- Sensory diet: a personalised programme of sensory activities throughout the day, designed to meet the child's regulatory needs and prevent overload
- Environmental modification: adjusting the sensory demands of the home and school environment
- Sensory integration therapy: structured therapy sessions using controlled sensory experiences
Where a Chew Necklace Fits
For children with SPD who have an oral sensory seeking profile — chewing, mouthing, biting — a chew necklace is often included in their sensory diet as a tool for providing safe, appropriate oral proprioceptive input during the school day. It fills the gap between therapy sessions, giving the child access to regulating proprioceptive input whenever the need arises.
If you suspect your child has sensory processing difficulties, the first step is a referral to a paediatric occupational therapist who specialises in sensory processing. A chew necklace can be a helpful part of the picture — but it is not a substitute for a full assessment and tailored support.