When Behaviour Changes: A Clinical Checklist for Minimally Verbal Autistic Children
A child who cannot tell you they are in pain will show you instead. The showing often looks like “challenging behaviour.”
This is one of the most important principles in autism care, and one of the most frequently overlooked. When a minimally verbal or non-speaking autistic child develops new or worsening behaviours, including increased self-injury, aggression, sleep disruption, food refusal, withdrawal, or distress, the first clinical question should not be “how do we manage this behaviour?” It should be “what is this behaviour telling us?”
Research consistently shows that autistic individuals, particularly those with limited verbal communication, experience significant diagnostic overshadowing: their symptoms are attributed to autism rather than investigated as potential signs of underlying medical conditions (1). The consequences can be severe. Pain goes untreated. Treatable conditions progress. Families are told their child is “just being autistic” when their child is actually unwell.
This article provides a systematic checklist for parents and clinicians to work through when an autistic child with limited verbal communication shows a change in behaviour. It is not exhaustive, but it covers the conditions most commonly missed.
The Core Principle: Behaviour Is Communication
Before working through the checklist, it is worth stating the underlying logic explicitly. Behaviour change in a child who cannot easily report symptoms should be treated as a potential symptom itself until proven otherwise. This approach is supported by NICE guidelines, the Royal College of Paediatrics and Child Health, and the consensus of specialist neurodisability services (2).
The key question is always: what has changed, and when did it start?
A clear timeline is invaluable. If a parent can say “this started three weeks ago on a Tuesday,” that information can point directly toward an event, a medication change, an infection, or an environmental shift.
The Checklist
1. Pain and Physical Discomfort
Pain is the single most commonly missed cause of behaviour change in minimally verbal autistic children. The following sources of pain should be systematically considered:
Dental Problems
Why it is missed: Autistic children often resist dental examination. Many have not had an adequate dental assessment. Dental pain can be constant or intermittent, severe or low-grade, and the child cannot point to their tooth and say “this one hurts.”
What to look for:
- Facial swelling (even subtle, unilateral puffiness)
- Refusal of foods previously accepted, especially hard, cold, or hot items
- Drooling or change in drooling pattern
- Rubbing or hitting the face or jaw
- Disturbed sleep (dental pain classically worsens at night when lying flat)
- Altered chewing pattern (favouring one side)
What to do: Request an urgent dental assessment. If a standard examination is not possible, a brief examination under sedation or general anaesthetic may be necessary. Dental X-rays can identify abscesses, caries, and impacted teeth that are invisible to external examination (3).
Evidence note: A systematic review found significantly higher rates of untreated dental caries in autistic children compared to controls, with many requiring treatment under general anaesthesia due to examination difficulties (4).
Otitis Media (Ear Infection/Glue Ear)
Why it is missed: Ear pulling or head banging may be attributed to stimming. Hearing loss from glue ear may not be obvious if the child’s communication is already limited. Chronic otitis media with effusion (glue ear) can persist for months without acute symptoms.
What to look for:
- New or increased head banging or ear pulling
- Tilting the head to one side
- Reduced response to sounds
- Increased volume of vocalisations
- Fever (in acute otitis media)
- Balance changes or increased clumsiness
- Disrupted sleep
What to do: Otoscopy by GP or paediatrician. If glue ear is suspected, tympanometry provides objective evidence. Referral to ENT and audiology may be needed (5).
Constipation
Why it is missed: Parents may not monitor stool frequency or consistency closely, especially in children still in nappies. Overflow soiling (liquid stool leaking around impacted hard stool) can mimic diarrhoea, leading to incorrect management. Many clinicians underestimate the pain of chronic constipation.
What to look for:
- Reduced appetite
- Abdominal distension
- Increased irritability, especially after meals
- Posturing (bending forward, pressing abdomen against surfaces)
- Soiling (especially if previously dry)
- Straining, hard stools, or infrequent bowel movements
- Avoidance of the toilet
What to do: Abdominal palpation. If uncertain, an abdominal X-ray can show faecal loading. Treatment with macrogol (Movicol) following NICE guidelines for disimpaction followed by maintenance. This often takes weeks to months to resolve fully (6).
Evidence note: Constipation affects up to 85% of autistic children in some studies and is one of the most common reversible causes of behaviour change (7).
Urinary Tract Infection
Why it is missed: UTI symptoms (dysuria, frequency, urgency) rely on the child being able to report discomfort. In a non-verbal child, the only signs may be behavioural.
What to look for:
- New onset wetting in a previously dry child
- Increased distress during nappy changes
- Smelly or cloudy urine
- Fever (may be the only sign)
- Increased irritability or crying, particularly when passing urine
What to do: Urinalysis (dipstick and microscopy/culture). A clean catch urine sample can be challenging but is essential for accurate diagnosis.
Gastro-Oesophageal Reflux
Why it is missed: Reflux can cause pain without vomiting (“silent reflux”). Symptoms such as arching, throat clearing, and food refusal may be attributed to behavioural issues.
What to look for:
- Arching the back, especially after meals or when lying down
- Food refusal (particularly aversion to previously accepted foods)
- Throat clearing or swallowing repeatedly
- Bad breath
- Worsening of symptoms when lying flat at night
What to do: A therapeutic trial of a proton pump inhibitor (PPI) can be both diagnostic and therapeutic. Referral to paediatric gastroenterology if symptoms persist (8).
Musculoskeletal Pain and Fractures
Why it is missed: Children who cannot report pain may not obviously guard an injured limb, especially if they have high pain tolerance or altered pain perception. Fractures from falls, particularly in children with motor difficulties, can go unrecognised for days or weeks.
What to look for:
- Limping or altered gait
- Refusal to weight-bear or use one hand
- Swelling or bruising
- Distress when a limb is moved passively
- Change in mobility or activity level
What to do: Clinical examination with X-ray of any suspected area. Consider the possibility of non-accidental injury (see safeguarding section below).
Skin Conditions
Why it is missed: Children who resist being undressed may not have their skin fully examined. Eczema, fungal infections, pressure sores, or insect bites can cause significant discomfort.
What to look for:
- Scratching or rubbing at specific body areas
- Disturbed sleep
- Increased self-injury targeting a specific area
- Resistance to clothing or bedding
What to do: Full skin examination (which may require patience, support, and a calm environment). Treat identified conditions.
2. Neurological Causes
Seizures (Including Subclinical Seizures)
Why it is missed: Epilepsy is common in autism, with prevalence estimates ranging from 20 to 30% depending on the study and the population (9). Not all seizures are convulsive. Absence seizures, focal seizures, and subclinical epileptiform activity can all cause behaviour change without obvious “seizure-like” movements. Post-ictal confusion or fatigue may be attributed to tiredness or regression.
What to look for:
- Staring episodes
- Sudden unexplained falls
- Loss of previously acquired skills (regression)
- Increased confusion or “zoning out”
- Sleep disruption (seizures may occur during sleep)
- Cyclical pattern of behaviour change (suggesting seizure clusters)
- Incontinence in a previously continent child
What to do: EEG (ideally sleep-deprived or prolonged ambulatory EEG, as routine 20-minute EEGs may miss intermittent seizure activity). Referral to paediatric neurology (10).
Raised Intracranial Pressure
Why it is missed: Rare but serious. Headache is the cardinal symptom, but a non-verbal child cannot report headache.
What to look for:
- Vomiting (especially early morning)
- Head banging (new onset or significantly increased)
- Visual changes (though difficult to assess: may present as bumping into things)
- Altered level of consciousness
- Papilloedema on fundoscopy (if examination is possible)
What to do: Urgent medical assessment. Fundoscopy. Neuroimaging if clinical concern.
3. Medication Effects
Why it is missed: Medication side effects can be subtle, delayed, or paradoxical. A child who cannot report feeling “strange,” dizzy, nauseated, or emotionally flat will instead show behaviour change.
Common culprits:
- Antipsychotics (risperidone, aripiprazole): akathisia (internal restlessness that the child cannot describe), weight gain, sedation, constipation
- Stimulants (methylphenidate): rebound irritability, appetite suppression, sleep disruption
- Anticonvulsants: mood changes, sedation, ataxia
- Melatonin: paradoxical hyperactivity (uncommon but documented)
- Antibiotics: GI disturbance, Clostridioides difficile infection
- Any recent medication change, including dose adjustments
What to do: Review all medications with dates of any changes. Consider a trial of discontinuation if a clear temporal relationship exists (under medical supervision) (11).
4. Sensory and Environmental Changes
Not all behaviour change has a medical cause. Environmental changes can be profoundly destabilising for autistic children, particularly those who rely on routine:
- Change of classroom, teacher, or teaching assistant
- Building work or changed acoustics in the home or school
- New lighting (e.g. LED replacements that produce flicker)
- Change of household member (new sibling, bereavement, separation)
- Seasonal changes (daylight, temperature, clothing changes)
- Change of route to school or daily routine
What to do: Construct a detailed timeline of the behaviour change alongside a timeline of environmental changes. Look for temporal correlations.
5. Mental Health
Anxiety and Depression
Why it is missed: Anxiety and depression in minimally verbal autistic individuals are extremely common but are almost impossible to assess using standard tools, which rely on self-report. Behaviour change may be the primary or only manifestation.
What to look for:
- Withdrawal from previously enjoyed activities
- Increased repetitive behaviours or rituals
- Sleep disturbance (waking early is a classic feature of depression)
- Appetite changes
- Reduced motivation
- Increased irritability
- Self-injury (which may represent emotional distress)
What to do: Assessment by a clinician experienced in autism and mental health. Observation across settings. Informant-based tools such as the Anxiety, Depression, and Mood Scale (ADAMS) can provide some structure, though they have limitations (12).
6. Abuse and Safeguarding
This is the section that nobody wants to write, but omitting it would be clinically irresponsible.
Autistic children, particularly those with limited communication, are at significantly increased risk of abuse, including physical, emotional, and sexual abuse, as well as neglect. A meta-analysis found that children with disabilities are 3.7 times more likely to experience violence than non-disabled children (13).
A child who cannot tell you what happened to them is a child who depends entirely on the adults around them noticing the signs.
What to look for:
- Unexplained bruising (particularly in unusual locations: trunk, face, upper arms, buttocks)
- Fearfulness or flinching around specific individuals
- Sexualised behaviour (new onset)
- Sudden regression or withdrawal
- Soiling or wetting (new onset) that does not respond to medical investigation
- Injuries inconsistent with the reported mechanism
What to do: If there is any concern, follow local safeguarding procedures. In the UK, contact the local authority designated officer (LADO) or local safeguarding team. Clinicians should follow RCPCH guidance on child protection and the intercollegiate document on safeguarding children (14).
This is not about blame. It is about the duty to ensure that every possible explanation for a child’s distress has been considered, including the most uncomfortable one.
7. Sleep
Sleep deterioration is both a common cause and a common consequence of behaviour change. It deserves specific consideration:
- Has the child’s sleep worsened? (onset, maintenance, or both)
- Is the sleep problem primary (i.e., the sleep disturbance is driving behaviour change) or secondary (i.e., pain or anxiety is disrupting sleep)?
- Has melatonin been started, stopped, or dose-changed?
- Has there been a change in bedtime routine, sleep environment, or screen time?
- Could obstructive sleep apnoea be present? (snoring, mouth breathing, witnessed pauses, enlarged tonsils)
What to do: Sleep diary for two weeks minimum. Assessment for obstructive sleep apnoea if clinically indicated (15).
A Practical Framework: The Behaviour Change Investigation
For clinicians and families, here is a structured approach to work through when a minimally verbal autistic child shows behaviour change:
Step 1: Define the Change
- What specifically has changed?
- When exactly did it start?
- Is it constant, intermittent, or escalating?
- Are there specific triggers or times of day?
Step 2: Medical Screen
- Full clinical examination (including ears, teeth, abdomen, skin, musculoskeletal)
- Observations: temperature, heart rate, blood pressure, weight
- Urinalysis
- Bloods if indicated: FBC, CRP, TFTs, vitamin D, ferritin, coeliac screen
- Consider dental review and audiology
- Consider EEG if seizures are possible
Step 3: Medication Review
- List all current medications with any recent changes
- Consider side effects, interactions, and paradoxical effects
Step 4: Environmental Timeline
- Construct a parallel timeline of any environmental changes
Step 5: Mental Health Assessment
- Consider anxiety, depression, and trauma
- Use informant-based tools where available
Step 6: Safeguarding
- Consider whether there are any safeguarding concerns
- Document and follow local procedures if there are
Step 7: Ongoing Monitoring
- If no cause is found, continue monitoring
- Repeat medical screen if behaviour persists or escalates
- Conditions can evolve; what was not apparent at the first assessment may become clearer over time
A Note on Diagnostic Overshadowing
The concept of diagnostic overshadowing, where symptoms are attributed to a person’s disability rather than investigated independently, is well documented and has caused serious harm. The LeDeR programme (Learning Disabilities Mortality Review) in England has repeatedly identified diagnostic overshadowing as a contributing factor in premature and avoidable deaths in people with learning disabilities and autism (16).
Every clinician seeing an autistic child with behaviour change should ask themselves: “If this child could speak fluently, what would I investigate?” The answer to that question should guide your clinical approach, regardless of whether the child can tell you in words.
References
- Mason J, Scior K. “Diagnostic overshadowing” amongst clinicians working with people with intellectual disabilities in the UK. Journal of Applied Research in Intellectual Disabilities. 2004;17(2):85-90.
- National Institute for Health and Care Excellence. Challenging behaviour and learning disabilities: prevention and interventions for people with learning disabilities whose behaviour challenges. NICE guideline NG11. 2015 (updated 2018).
- Lam PP, Du R, Peng S, McGrath CP, Yiu CK. Oral health status of children and adolescents with autism spectrum disorder: a systematic review of case-control studies and meta-analysis. Autism. 2020;24(5):1064-1076.
- da Silva SN, et al. Oral health status of children and young adults with autism spectrum disorders: systematic review and meta-analysis. International Journal of Paediatric Dentistry. 2017;27(5):388-398.
- National Institute for Health and Care Excellence. Otitis media with effusion in under 12s: surgery. NICE guideline NG233. 2023.
- National Institute for Health and Care Excellence. Constipation in children and young people: diagnosis and management. Clinical guideline CG99. 2010 (updated 2017).
- Pang KH, Croaker GDH. Constipation in children with autism and autistic spectrum disorder. Pediatric Surgery International. 2011;27(4):353-358.
- Buie T, et al. Evaluation, diagnosis, and treatment of gastrointestinal disorders in individuals with ASDs: a consensus report. Pediatrics. 2010;125(Supplement 1):S1-S18.
- Spence SJ, Schneider MT. The role of epilepsy and epileptiform EEGs in autism spectrum disorders. Pediatric Research. 2009;65(6):599-606.
- Tuchman R, Cuccaro M, Alessandri M. Autism and epilepsy: historical perspective. Brain and Development. 2010;32(9):709-718.
- Hsia Y, et al. Psychopharmacological prescriptions for people with autism spectrum disorder (ASD): a multinational study. Psychopharmacology. 2014;231(6):999-1009.
- Esbensen AJ, et al. Reliability and validity of an assessment instrument for anxiety, depression, and mood among individuals with mental retardation. Journal of Autism and Developmental Disorders. 2003;33(6):617-629.
- Jones L, et al. Prevalence and risk of violence against children with disabilities: a systematic review and meta-analysis of observational studies. The Lancet. 2012;380(9845):899-907.
- Royal College of Paediatrics and Child Health. Child Protection Companion. 3rd ed. RCPCH; 2023.
- Malow BA, et al. A practice pathway for the identification, evaluation, and management of insomnia in children and adolescents with autism spectrum disorders. Pediatrics. 2012;130(Supplement 2):S106-S124.
- University of Bristol. The Learning Disabilities Mortality Review (LeDeR) Programme: Annual Report 2021. NHS England; 2022.