ADHD and Autism: Understanding the Overlap
ADHD and autism spectrum disorder (ASD) are two common neurodevelopmental conditions, and they can occur together in the same person. Research suggests that up to 50–70% of autistic people also have ADHD, while around 20–50% of people with ADHD may also meet the criteria for autism. The two conditions share some features, such as difficulties with attention, organisation, social interaction and emotional regulation, which can sometimes make them difficult to distinguish.
Understanding the overlap between ADHD and autism is important for accurate assessment and appropriate support. Recognising both conditions can also help explain why certain difficulties may continue even when one condition has already been identified and treated.
How ADHD and autism are similar
ADHD and autism share a number of features that can make them difficult to distinguish:
- Attention difficulties: Both conditions can involve difficulty sustaining attention, though for different reasons. In ADHD, attention can be less consistent, often shifting towards what is most stimulating rather than what is most needed. In autism, attention may be intensely focused on specific interests while other areas are neglected.
- Social difficulties: Both conditions can involve challenges in social situations, though again for different reasons. In ADHD, social difficulties often stem from impulsivity, interrupting, and difficulty reading social cues in real time. In autism, social difficulties often stem from differences in social communication and understanding of social norms.
- Sensory sensitivities: Both conditions can involve sensory sensitivities, though this is more consistently present in autism.
- Executive function difficulties: Both conditions involve difficulties with planning, organisation, and cognitive flexibility.
- Emotional regulation: Both conditions can involve difficulty regulating emotions, though the presentation differs.
How ADHD and autism are different
Despite the overlap, ADHD and autism are distinct conditions with different underlying mechanisms and different presentations:
| Feature | ADHD | Autism |
|---|---|---|
| Attention | Dysregulated, stimulus-seeking | Can be intensely focused on specific interests |
| Social motivation | Generally wants social connection but struggles with execution | May have reduced social motivation or different social needs |
| Repetitive behaviours | Not a core feature | Core feature (stimming, routines, restricted interests) |
| Response to change | Impulsive, seeks novelty | Often prefers routine and sameness |
| Emotional expression | Often expressive, reactive | May have flat affect or atypical emotional expression |
| Sensory sensitivities | Can occur | Core feature in many |
The dual diagnosis: ADHD and autism together
When ADHD and autism co-occur, the symptoms can be complex and an ADHD diagnosis may not explain every difficulty a person experiences. Some features of each condition can mask or amplify features of the other. For example, the hyperfocus associated with autism can mask the attention difficulties of ADHD, while ADHD-related impulsivity can sometimes mask a preference for routine that is more characteristic of autism.
A dual diagnosis is not uncommon and does not mean that an earlier assessment was inaccurate. Both conditions can occur together, and recognising this can provide a clearer understanding of a person’s needs. Having both ADHD and autism may also affect the type of treatment and support that is helpful, as their needs can differ from those of someone with either condition alone.
When you suspect both ADHD and autism
If you recognise signs of both ADHD and autism, you may be unsure about what to do next. Some symptoms can overlap, making it difficult to understand which condition may be affecting you. Getting the right information and speaking with a qualified clinician can help you understand your experiences more clearly.
- Consider a formal assessment: If you think you may have both ADHD and autism, an assessment with a clinician experienced in working with adults can help explore your symptoms in more detail. This can provide a clearer picture of your individual needs and whether your difficulties may relate to ADHD, autism or both.
- Learn more about your symptoms: Online screening tools can help you recognise possible ADHD or autistic traits, but they cannot confirm a diagnosis. They can be a useful starting point if you are considering a formal assessment or want to understand your symptoms better.
- Find the right support: Working with a clinician or therapist who understands both ADHD and autism can help you explore your needs and discuss suitable support. Trusted resources and neurodivergent communities can also provide useful information, but online advice should not replace professional assessment or medical guidance.
Late diagnosis of autism in adults with ADHD
Some adults who are diagnosed with ADHD later discover that they are also autistic. This may be particularly relevant for women, who can be more likely to mask or compensate for symptoms of both conditions. If you have an ADHD diagnosis but continue to experience difficulties despite treatment, or recognise traits associated with autism, an ADHD assessment UK can help you discuss your symptoms with a qualified clinician and explore whether further assessment may be appropriate.
What a comprehensive assessment should cover
A comprehensive ADHD assessment should also consider autism and other conditions that may occur alongside ADHD. At ADHD Assessment UK, our assessments look at a range of neurodevelopmental and mental health conditions that may be linked to your symptoms, helping provide a clearer understanding of your individual needs.
Getting the right support
A dual diagnosis of ADHD and autism opens the door to a wider range of support. This may include ADHD medication (which can help with attention and impulse control even in the context of autism), autism-specific support services, workplace adjustments that address both conditions, and psychological support tailored to the specific combination of needs.
If you are unsure whether you have ADHD, autism, or both, you can book an ADHD consultation with a clinician experienced in neurodevelopmental conditions to explore your symptoms and individual needs.
Conclusion
ADHD and autism are different conditions, but they can occur together and share some similar traits. Understanding the differences and overlap can help explain difficulties with attention, communication, emotional regulation, routines and everyday life.
If you recognise signs of both conditions, a comprehensive assessment can help provide a clearer understanding of your symptoms and individual needs. The right diagnosis can also help you explore suitable treatment, support and practical strategies for managing daily life.
Our assessments explore ADHD alongside co-occurring conditions including autism, anxiety, and RSD.
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