ADHD and other conditions that often occur with autism
About three in four autistic children have at least one other condition alongside autism. Many of those are treatable — and they often drive the hardest days more than autism itself.
The short answer
- Roughly three in four autistic children have another condition alongside autism. ADHD, anxiety, sleep problems, and gut issues are among the most common.
- These are not ‘part of autism’ in a way that makes them untreatable. Many respond to the same approaches used for non-autistic children, adapted as needed.
- When behaviour is difficult, ask what else might be present — pain, ADHD, anxiety, sleep debt — before assuming it is just autism.
- Practical order: check sleep, constipation, and pain first; then ADHD and anxiety if those still dominate.
Under 5 — what to check and do
Ages 0–4- Sleep problems, feeding difficulties, and constipation are frequent. Constipation often shows up as behaviour rather than a complaint of pain.
- Seizures or significant developmental regression need prompt medical evaluation.
- Action: track sleep and stools for two weeks; ask the pediatrician about both; complete hearing and vision checks.
Changes when you change the age at the top of the page.
School age — what to check and do
Ages 5–8- ADHD becomes easier to identify as school demands increase. Anxiety may show as refusal, rigidity, or meltdowns around transitions.
- Learning differences should be assessed separately so support is targeted.
- Action: ask the school for observations on attention and anxiety; discuss ADHD evaluation if focus and impulsivity are major problems.
Changes when you change the age at the top of the page.
Later primary years — what to check and do
Ages 9–12- Anxiety and low mood often rise. Masking makes internal distress easy to miss.
- ADHD support needs may shift toward organisation and homework rather than hyperactivity.
- Action: ask your child about worry and tiredness; review ADHD supports if organisation is falling apart; protect after-school downtime.
Changes when you change the age at the top of the page.
Teenagers — what to check and do
Ages 13–16- Anxiety, depression, and autistic burnout are major drivers. Mental health support is often the highest priority.
- ADHD medication and strategies may need review as sleep and demands change.
- Action: prioritise mental health assessment if mood or burnout is present; review sleep and medication with the prescriber; involve your teenager.
Changes when you change the age at the top of the page.
The 3-in-4 figure
About three in four children with autism have at least one other developmental, medical, or mental health condition alongside autism. Common ones: ADHD, anxiety, sleep problems, gastrointestinal issues (including constipation), learning or language disorders, epilepsy, and mood difficulties in older children.
When days are hard, these often explain more of the distress than the autism diagnosis itself. Treating everything as “just autism” leaves treatable problems untouched.
Autism and ADHD together
A substantial share of autistic children also meet criteria for ADHD. The overlap intensifies difficulties with attention, impulsivity, organisation, and emotional regulation.
Both can be identified. Support for ADHD — environmental strategies, school accommodations, and in some cases medication — can make a large practical difference. “We already have an autism diagnosis” is not a reason to ignore ADHD.
Ask for: a proper ADHD evaluation if attention or impulsivity are major drivers; school accommodations that address both; a clear medication plan if medication is considered (target symptoms, monitoring, review date). Side effects (appetite, sleep, mood) need watching. Organisation supports are also on the executive function page.
Anxiety
Anxiety is extremely common. It may look like classic worry — or like extreme rigidity, avoidance, meltdowns around uncertainty, or physical complaints. Treating it as “just autism” leaves children without adapted strategies and, when appropriate, medication that can help.
Full guide: Anxiety in autistic children and teens.
Name anxiety as a possible driver when refusal or distress spikes around uncertainty. Reduce unnecessary unpredictability while building coping skills. Ask a clinician experienced with children with autism about assessment and support. Do not wait for the child to verbalise worry if anxiety shows up as behaviour.
For anxiety in depth, see Anxiety in autistic children and teens. For teenagers — depression, burnout, crisis signs, and how to get help — see teen mental health.
Sleep, gut, and pain — check these first
- Sleep amplifies every other difficulty — sleep.
- Constipation and gut pain are more common and often present as behaviour — gut.
- Untreated physical pain (dental, ear, headache, injury) is a classic driver of increased distressed behaviour — pain.
Track sleep and stools for 1–2 weeks. Ask specifically about pain sources at the next medical visit, including dental. Treat what you find before escalating behavioural explanations.
Decision order when everything feels related
- Sleep, constipation, pain, hearing, vision
- Communication access (including AAC if needed)
- ADHD if attention and impulsivity are major problems
- Anxiety or mood if worry, avoidance, or low mood dominate
- Learning assessment if academic progress is the main concern
You do not have to solve everything in one month. Pick the top driver of hard days and move that first.
What to take to appointments
A one-page list of the top three concerns with examples and dates. Sleep and stool notes if relevant. School observations if available. Current medications. One clear question: “Could ADHD / anxiety / sleep / constipation be contributing, and how do we evaluate that?”
One-page “what else could it be?” for the doctor
List top three hard-day drivers with examples:
- Sleep — hours, wakings
- Constipation — log summary
- Anxiety / ADHD / pain — what you see
Ask: “Could any of these be amplifying what we’re calling behaviour?” Write the answer down.
Parent trap to avoid
Treating every hard day as ‘just autism’ so treatable sleep, gut, ADHD, or anxiety never get names.
Questions parents ask after reading this
Use these with your co-parent, teacher, or clinician so the next conversation is concrete.
- What is the single highest-yield change we can make in the next seven days based on this page?
- What should we stop doing that is adding load without helping?
- Who else needs a one-page summary of this plan (school, caregiver, relative)?
- What would “a little better” look like in two weeks so we know the plan is working?
Write the answers down. Plans that live only in your head disappear on hard days.
If you only do three things
- Pick one action from this article and schedule it on the calendar (call, email, or routine change).
- Tell one other adult the plan in one sentence so you are not carrying it alone.
- Revisit this page after two weeks and note what changed — keep, adjust, or drop.
Small completed steps beat perfect unread plans. You are allowed to go slowly and still be a good parent.
Questions parents ask
Where this comes from
- CDC ADDM Network summaries on co-occurring conditions, 2022 surveillance data (published 2025).
- Population and clinical studies of ADHD–autism co-occurrence.
- Reviews of anxiety, sleep, and gastrointestinal problems in autistic children.
This is health information, not medical advice. It cannot replace a conversation with your child's doctor.