AuDHD: when autism and ADHD occur in the same adult

AuDHD is an informal name for autism and ADHD occurring in the same person. It is not a separate diagnosis, and each condition has to be assessed in its own right. The two often overlap, and in adults one of them is frequently missed because the other explains enough of the picture.

What AuDHD means, and what it does not

The term combines “autism” and “ADHD”. It describes a person who meets criteria for both, not a third condition. The diagnostic manuals treat them as two separate neurodevelopmental diagnoses, and since the DSM-5 (2013) both can formally be given to the same person [2]. Before that, many clinicians were taught that one excluded the other, which left a lot of people with half an explanation.

NICE takes the same practical line for ADHD: a diagnosis should not be ruled out simply because a developmental condition such as autism is present [3]. Both conditions begin in childhood, even when they are recognised only in adulthood.

How common is it?

A large meta-analysis of 96 studies found that about 28% of autistic people had a diagnosis of ADHD (95% confidence interval 25–32%), the highest figure among the psychiatric conditions it examined [1]. The studies differed a lot from each other, so treat this as an order of magnitude, not a precise rate for any one person. It also runs in one direction only: it tells you how many autistic people have ADHD, not how many people with ADHD are autistic.

Why the picture is confusing

The same behaviour can come from different causes, which is why counting shared traits does not get you far. When two people do the same thing for different reasons, the useful question is “why”, because the answer decides what will help. A few questions an assessment asks:

• Routine. Do you keep a strict schedule because without it you forget and fall apart (more typical of ADHD), because changes in plans are distressing in themselves (more typical of autism), or both?

• Noise and crowds. Do you lose your train of thought because everything pulls your attention, or because the sensory load becomes too much? NICE’s autism guideline lists both over- and under-sensitivity to sensory input among the features to ask about [4].

• Social life. Do conversations go wrong because you interrupt and lose the thread, because the unwritten rules are hard to read, or because you are exhausted from keeping up an act?

In people who have both, these pulls can work against each other: needing structure and being unable to keep it, or craving stimulation and being overwhelmed by it. These are starting points for a conversation, not a diagnosis.

One more question helps with social life: were you always reserved, or did you pull back after years of difficulty? Shyness that has been there from early on is a different thing from avoidance learned after many conversations went wrong. The answer changes what the support should aim at.

Why one of them is missed in adults

Many adults learn to hide their difficulties. A systematic review of social camouflaging in autistic adults and young people found that it is motivated by self-protection and the wish to connect with others, that it is reported more often in women, and that it is linked to poorer mental health [5]. A second review reached a similar conclusion about its psychosocial cost [6]. When you hide the effort for years, the effort does not disappear. It shows up later as exhaustion, and a clinician meeting you for the first time may see only the polished result.

Another pattern is being given other diagnoses first. In a Dutch register of 1,211 autistic adults, 24.6% reported at least one earlier psychiatric diagnosis that they now consider a misdiagnosis: 31.7% of the women and 16.7% of the men. Personality disorder, anxiety and mood disorders were the most frequent [7]. These are self-reported figures from volunteers, so they show a pattern, not an exact rate. They do not mean that earlier diagnoses were wrong in every case. Anxiety and depression are common alongside both ADHD and autism.

Notice the thoughts that keep people stuck here, because they are often traps. “Everyone else manages, so I am just lazy” is overgeneralising. “If I can’t do it perfectly, I have failed” is all-or-nothing thinking. “I should cope like everybody else” is a rule you were handed, not a fact. Test them with a concrete question: if a plan changes and you need an evening alone to recover, is that weakness, or information about what your system needs?

Not being well in an environment that does not suit how your mind works is not a failure. It is an expected reaction.

How the assessment works

• Developmental history. Attention, impulsivity, social communication, repetitive patterns, sensory experiences and how all of this looked at school. Old school reports help, and so does a parent or someone who knew you as a child, if that is possible. NICE advises the same for autism assessment [4].

• A structured interview for ADHD. At this practice I use the DIVA-5, which goes through the 18 DSM-5 symptoms for childhood and adulthood, with examples and impairment in different areas of life [8].

• Other conditions. Anxiety, depression, sleep problems and substance use can look like either condition or sit on top of them. The DIVA Foundation itself stresses that a general psychiatric assessment is needed alongside the interview [8].

• A specific look at autism when there are signs. NICE recommends a comprehensive autism assessment by trained, competent professionals, preferably team-based and with an informant or documents about early development [4]. A short questionnaire can only prompt that step, not replace it.

The ASRS questionnaire on this site screens for ADHD only. A result says nothing about autism, in either direction. Questionnaires are described on the tests page, and the ADHD process, fees and format are explained in how an adult ADHD assessment works.

What I assess and what I refer on. The focus of the practice is adult ADHD. If your history points towards autism, I will say so openly, explain what I am seeing and discuss next steps, which may include a referral for a specialist autism assessment. If you need a formal autism diagnosis or a report for a particular organisation, please contact the practice before booking so that we can agree what is possible. I am currently completing postgraduate studies in autism.

What helps once you know

Autism is not something to be treated away. Support means adjustments and tools that reduce overload: predictable but flexible routines, a quieter workspace, written instructions, and therapy that fits how you think. ADHD has its own evidence-based treatments, but treating ADHD does not treat autism, and the sensory and social differences need other kinds of support [2].

The plan is built together. You get the options in front of you, including support and therapy-based work, and where medication is one of them it is a shared decision with its possible side effects discussed up front, with a timeline and a trial period. When both conditions are present, NICE notes a greater risk of altered sensitivity and unpredictable responses to medication in autistic adults, so it is approached with extra care [4]. Whether it is offered at all is decided after the assessment, not before it.

After the assessment you leave with a shared understanding of your profile, concrete next steps and a set date to review how they are working.

Finding out late can bring grief for what might have been easier. It is normal to grieve experiences you missed. It is part of healing. Self-compassion is not pity. It is recognising your own strength.

When therapy is part of the plan, the CBT I use for ADHD and autism is structured, short and focused on skills for the present. One example is role play: you practise a more diplomatic way to say something, so that being direct does not cost you a relationship.

When to look for an assessment, and a first step

The question is not “do I feel different?” The question is whether these difficulties regularly get in the way of work, relationships or daily functioning. Discomfort alone is not the test. Getting in the way, again and again, is.

You do not need a label to start. Waiting until you feel ready tends to keep you stuck, because avoiding the question never answers it. Action comes before mood, so take one small step now: write down a few real situations, such as a noisy week at work, a plan that changed, a social event and how long it took to recover, a task you could not start. Add what you remember from school and bring any old reports. Please do not rely on online tests to settle the question. They are a prompt for a conversation, not a result.

I see adults in Trikala, Karditsa, Kalambaka and online anywhere in Greece, in English or Greek. The assessment for ADHD is usually two 45-minute sessions at 130 € each. The adult ADHD service page has the details, and you can book an appointment directly.

Educational information. It does not replace an individual assessment.

Sources

1. Lai MC, Kassee C, Besney R, et al. Prevalence of co-occurring mental health diagnoses in the autism population: a systematic review and meta-analysis. Lancet Psychiatry 2019;6(10):819-829. https://doi.org/10.1016/S2215-0366(19)30289-5

2. Young S, Hollingdale J, Absoud M, et al. Guidance for identification and treatment of individuals with attention deficit/hyperactivity disorder and autism spectrum disorder based upon expert consensus. BMC Med 2020;18:146. https://doi.org/10.1186/s12916-020-01585-y

3. NICE. Attention deficit hyperactivity disorder: diagnosis and management (NG87), recommendations 1.3.1–1.3.4. https://www.nice.org.uk/guidance/ng87/chapter/recommendations (retrieved 29/10/2026)

4. NICE. Autism spectrum disorder in adults: diagnosis and management (CG142), recommendations 1.2.3, 1.2.5, 1.2.7, 1.3.2. https://www.nice.org.uk/guidance/cg142/chapter/recommendations (retrieved 29/10/2026)

5. Klein J, Krahn R, Howe S, et al. A systematic review of social camouflaging in autistic adults and youth: Implications and theory. Dev Psychopathol 2024;37(3):1320-1334. https://doi.org/10.1017/S0954579424001159

6. Zhuang S, Tan DW, Reddrop S, et al. Psychosocial factors associated with camouflaging in autistic people and its relationship with mental health and well-being: a mixed methods systematic review. Clin Psychol Rev 2023;105:102335. https://doi.org/10.1016/j.cpr.2023.102335

7. Kentrou V, Livingston LA, Grove R, et al. Perceived misdiagnosis of psychiatric conditions in autistic adults. eClinicalMedicine 2024;71:102586. https://doi.org/10.1016/j.eclinm.2024.102586

8. DIVA Foundation. About DIVA-5. https://www.divacenter.eu/diva-5/about-diva-5/ (retrieved 29/10/2026)