AuDHD in Adults: Understanding Autism and ADHD Together
You have an ADHD diagnosis, but it does not seem to explain everything you experience. Or perhaps you are still looking for an explanation and come across the word “AuDHD”. The descriptions feel familiar. Relief arrives, followed by a question: does this mean I am autistic too?
AuDHD is an informal term for co-occurring autism and ADHD, not a separate diagnosis. Both diagnoses can apply to the same person. Someone can also have one condition and some characteristics associated with the other without meeting its diagnostic criteria. Recognising yourself in a description does not establish which situation applies to you.
That distinction matters in practice. You do not need to work out the right label on your own before discussing your difficulties. Describing what happens in your life, how far back you remember it and what support you need is a more useful place to start.
AuDHD: one term, two diagnoses
The term combines autism and ADHD. The National Autistic Society and American Psychiatric Association use it when discussing the two conditions occurring together. Cleveland Clinic notes that AuDHD is not a separate DSM-5 diagnosis. A clinical assessment therefore considers autism and ADHD, rather than confirming a third condition with a single test.
For some people, the term offers a convenient way to talk about their experience. It can help them find others with similar experiences and put previously unspoken questions into words. You can find it helpful while remaining uncertain about your own diagnosis. Using the term does not replace clinical assessment, but explaining that boundary does not require dismissing someone's chosen language.
It does not mean “more severe ADHD” or another ADHD presentation, either. ADHD symptoms in adults concern a particular pattern of difficulties with attention, impulsivity or excessive activity. Co-occurring autism requires an assessment of its own characteristics. The severity of someone's difficulties does not by itself demonstrate that both conditions are present.
Imagine two people with ADHD who need quiet after meetings. They describe a similar outcome, but that is not enough to assign the same cause or an additional diagnosis to both. This illustrates the limits of comparing brief descriptions; it is not an example for identifying autism.
Shared experiences are not a home diagnostic test
Descriptions of AuDHD often pair a need for routine with a search for novelty, or a wish for connection with exhaustion after socialising. These contrasts may help someone express their experience. They are not a universal profile of an autistic person with ADHD, or a checklist everyone must satisfy.
The APA discusses shared characteristics and possible co-occurrence. NICE guidance on adult autism assessment requires consideration of other explanations and coexisting conditions. “This fits ADHD, that fits autism, so I must have both” skips too much. Assessment is not a matter of assigning every behaviour to one of two columns.
A single characteristic cannot confirm or rule out autism and ADHD. Its context, history and impact on daily functioning matter. “I dislike change” does not yet explain how you respond to it, in which situations, since when or how much it disrupts your life. Those details give a discussion more substance than the word “symptom” alone.
Intense concentration is another example. Being able to become deeply absorbed in an activity does not establish whether you have ADHD, autism or both. Hyperfocus and its diagnostic limitations deserve their own explanation; they are not a missing piece that proves AuDHD.
You do not have to minimise your difficulties because their cause is uncertain. You can say “I have no energy to talk after meetings” or “a change of plan throws off my whole day” without attaching a definite explanation. Those observations are useful in an assessment precisely because they leave room for questions rather than deciding the answers in advance.
Why adult assessment looks back at childhood
An assessment is not limited to how you have felt this week. NICE recommends that ADHD assessment include developmental and psychiatric history and functioning across different areas of life. Adult autism assessment considers characteristics present in childhood and continuing into adulthood, alongside current needs and circumstances.
This does not mean you needed a diagnosis at school. Recognising difficulties later and having a history that began earlier are different things. A clinician may ask about learning, relationships, everyday responsibilities or situations involving changes of plan. The course of your experiences matters, not a perfectly prepared account of childhood.
Guidance describes information from other people and records as useful where available. School reports, previous assessments or other relevant documents can provide additional information. Incomplete memories are not a reason to rule out seeking help before you start. Explain what you cannot remember and ask the service how it works with incomplete information.
Arrangements vary by country and provider. For autism, NICE recommends involving an informant or using documentary evidence “where possible”; that is not the same as demanding that everyone arrive with a complete archive. Ask what alternatives the service can consider if childhood records or someone who knew you then are unavailable. Do not assume that the requirements for assessing one condition automatically apply to the other.
Your agreement to involve other people also matters. You can ask why a conversation with someone close to you would be helpful, what information will be collected and what other options exist. If family contact is unavailable or unsafe, explain that beforehand. The aim is to build as reliable a history as possible, not to pass a test of having the right documents.
Preparing to discuss possible co-occurrence
Instead of copying a long online list of AuDHD traits, choose a few situations you genuinely want to understand. Note what happened, the circumstances, the consequences and whether you remember similar experiences earlier in life. Leave space for “I don't know”. You do not need to reshape memories to match something you have read.
An example note might be: “When plans change at work, I struggle to return to the task; I want to discuss what gets in the way.” That is an illustration of preparation, not a sign pointing to a particular diagnosis. Include situations you manage well and any support you already use. An assessment concerns your functioning, not just your most difficult moments.
Useful questions for a service include:
- Do you assess adults for autism and ADHD, or only one of them?
- How does the process work if I already have one diagnosis?
- What should I bring, and what happens if childhood records are missing?
- How will I receive an explanation of the findings and a discussion of my needs?
These are practical suggestions, not a compulsory script. Services organise assessments differently, and healthcare pathways depend on where you live. NICE recommends discussing the purpose of an autism assessment and how feedback will be provided. Asking beforehand can clarify what a particular appointment covers without assuming it offers a combined assessment of both conditions.
Include previous diagnoses and relevant health information in the discussion. Guidance recommends considering coexisting conditions and other possible explanations. You do not need to decide which one accounts for each difficulty before you attend. Our article on preparing for an ADHD assessment offers more context for that stage.
You can bring the question “What might explain my difficulties?” to an assessment, rather than a ready-made diagnosis to confirm.
If you also want to organise observations specifically related to ADHD, you can use an ADHD screening test. Our screening does not assess autism or establish AuDHD, and it cannot diagnose ADHD. Its result does not determine whether you need an autism assessment. If autism is your main concern, seek advice about assessment for that concern; an ADHD screening is not a required first stop.
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Before the appointment, you can also note what you hope to get from it. Perhaps you want to understand your functioning, ask what assessment is appropriate or discuss a particular difficulty at work. You do not have to address every goal at once. If you are unsure where to begin, say which question matters most today. Separate your observations from other people's interpretations: “I remember…” is different from “someone told me this must be autism”. You can share both, but they are not the same kind of information. Preparation should support the conversation, not secure a particular assessment outcome.
FAQ — Common questions about AuDHD in adults
If I already have an ADHD diagnosis, must I start again?
Bring your previous assessment information and explain which questions remain unanswered. Whether further information or additional assessment is needed depends on your circumstances and the service's approach. An existing ADHD diagnosis does not confirm autism.
Can I ask for support before I know my diagnosis?
You can describe specific needs and ask what support is available without presenting yourself as having confirmed AuDHD. Requirements for particular services or forms of support vary. You do not need certainty about the cause in order to explain a difficulty.
Does every ADHD specialist also assess autism in adults?
Do not assume so from a service's name alone. Before booking, ask about its scope and experience with adult assessment and co-occurring conditions. An appointment focused on one condition may not include a full assessment of the other.
AuDHD — key takeaways
AuDHD describes autism and ADHD occurring together, but does not replace assessment of each condition. Familiar descriptions can be a starting point for questions rather than a final answer. Prepare a few everyday examples and ask how adult assessment works in your circumstances. Your needs are worth discussing even while their explanation remains uncertain.
Sources
- When Autism and ADHD Occur Together — American Psychiatric Association, 2025. https://www.psychiatry.org/news-room/apa-blogs/when-autism-and-adhd-occur-together
- Related conditions — a guide for all audiences — National Autistic Society. https://www.autism.org.uk/advice-and-guidance/related-conditions/related-conditions/all-audiences
- Understanding AuDHD — Cleveland Clinic, 2025. https://health.clevelandclinic.org/audhd
- Autism spectrum disorder in adults: diagnosis and management, CG142, section 1.2 — NICE, 2012, updated 2021. https://www.nice.org.uk/guidance/cg142/chapter/recommendations
- Attention deficit hyperactivity disorder: diagnosis and management, NG87, section 1.3 — NICE, 2018. https://www.nice.org.uk/guidance/ng87/chapter/recommendations
