Sensory processing disorder is widely treated, yet the major diagnostic manuals leave it out
For some people a clothing label feels unbearable, ordinary light hurts, or even their own heartbeat is distracting. Occupational therapists call this sensory processing disorder. Yet the DSM-5 and ICD-10 do not recognise it, and in 2012 the American Academy of Pediatrics advised against using it as a stand-alone diagnosis.
The idea traces to the occupational therapist Anna Jean Ayres, who in 1972 described sensory integration as the brain's organising of sensations from the body and the surroundings so the body can act effectively. When that organising falters, problems can show up in any sense: sight, sound, smell, taste and touch, but also balance, awareness of limb position, and signals from inside the body. To count as a disorder, the difficulties must clearly interfere with work, play or daily routines; a stray symptom or two is not enough.
The patterns are varied. Some people are over-responsive, recoiling from fabrics, foods or grooming products that others barely notice. Others are sluggish and under-responsive. Some crave stimulation, fidgeting or making loud noises, and some struggle with discrimination, which can look like constantly dropping things. Proponents of a formal category group these into three families: problems adjusting to the intensity of stimuli, motor difficulties rooted in faulty sensory input, and trouble telling sensations apart.
The controversy centres on overlap. Sensory difficulties are common in autism, ADHD, Tourette's syndrome, dyspraxia and anxiety, so critics ask whether the label merely names shared symptoms. A small study of preterm schoolchildren found two thirds scored outside the typical range, most of them with ADHD. Two studies have hinted at measurable brain differences, and researchers have reported unusual white matter in affected children compared with autistic peers or those with ADHD, but the lack of an agreed diagnostic tool weakens such findings. Tactile over-responsivity appears moderately heritable.
Diagnosis, usually by an occupational therapist, relies on standardised tests, questionnaires and watching a child play, sometimes at home or school. The condition is accepted in a classification system for infant and early childhood mental health. Clinicians who treat such children, including dentists, are advised to prepare them beforehand, reduce noise and visual clutter, and choose the least invasive procedures.
Source: Sensory processing disorder
