One of the most common questions we hear from adults and parents is:
"How do I know if it's ADHD or autism?"
It is a reasonable question.
ADHD and autism can share many similarities. Both can affect attention, emotional regulation, communication, relationships, learning, and everyday functioning. Both can be missed during childhood. Both can continue into adulthood. Both can leave people feeling different without fully understanding why.
Because there is so much overlap, many people spend years trying to work out which explanation fits their experiences.
Some people are surprised to learn the answer may be both.
Research shows that ADHD and autism frequently occur together. This means someone can be autistic and have ADHD at the same time. In fact, this is something we see regularly in clinical practice.
Understanding the similarities and differences can help people make sense of their experiences and decide whether an assessment may be helpful.
What Is the Difference Between Autism and ADHD?
Although autism and ADHD are both neurodevelopmental conditions, they affect people in different ways.
ADHD primarily affects attention, organisation, planning, motivation, impulse control, and emotional regulation. People with ADHD often describe struggling to stay focused, manage their time, complete tasks, and keep on top of everyday responsibilities.
Autism affects social communication, sensory processing, flexibility, routines, relationships, and the way information is understood and interpreted. Autistic people often describe feeling different from those around them, particularly in social situations or environments that feel overwhelming.
The challenge is that these differences are not always obvious.
Many people experience traits that could fit either condition. This is one reason assessments look at a person's full history rather than focusing on a few isolated symptoms.
Why Do Autism and ADHD Look So Similar?
When people first start learning about autism and ADHD, they are often surprised by how much overlap exists.
For example, both can affect social situations.
A person with ADHD may interrupt conversations, lose track of discussions, or struggle to follow social cues because their attention shifts quickly.
An autistic person may find social situations challenging for different reasons. They may struggle with unspoken social rules, interpreting facial expressions, understanding tone of voice, or knowing what is expected in a particular situation.
From the outside, both people may appear socially awkward or uncomfortable.
The reasons behind those experiences are often quite different.
The same thing happens with emotional regulation. Both autistic people and people with ADHD may become overwhelmed more easily than others. They may struggle when routines change unexpectedly, when demands become too high, or when stress builds up over time.
Without looking deeper, it can be difficult to understand what is actually driving those challenges.
Can You Have ADHD and Autism at the Same Time?
Yes.
This is one of the biggest misunderstandings we encounter.
For many years, people were often diagnosed with one condition or the other. Today, we know that ADHD and autism commonly occur together.
Some people meet the criteria for both.
When this happens, the experiences can become more complex.
Someone may struggle with organisation, attention, and time management because of ADHD, while also experiencing sensory sensitivities, social communication differences, and a strong need for routine associated with autism.
Many adults who receive both diagnoses describe feeling as though different parts of their experience finally make sense.
Rather than trying to force themselves into one explanation, they gain a more complete understanding of how their brain works.
Could I Have Autism, ADHD, or Both?
Many adults begin asking this question after seeing information online or learning more about neurodiversity.
Often they recognise parts of themselves in both descriptions.
They may relate to the organisation difficulties associated with ADHD while also identifying with autistic experiences around sensory sensitivities, social situations, or routines.
This can be confusing.
The reality is that there is no online checklist capable of providing a reliable answer.
At The Hummingbird Centre, we often meet adults who have spent months or years trying to work this out on their own. They have read articles, watched videos, completed online quizzes, and spoken with friends who have been diagnosed.
While this information can be helpful, it cannot replace a comprehensive assessment.
The goal of an assessment is not simply to decide whether someone has ADHD or autism. The goal is to understand how that person's brain works, what challenges they experience, what strengths they bring, and what support may be helpful.
Why Are Autism and ADHD Often Missed in Adults?
Many adults assume they would have been diagnosed during childhood if they were autistic or had ADHD.
In reality, many people learn to adapt.
Some work incredibly hard to stay organised.
Others develop routines that help them manage daily life.
Many become skilled at masking their difficulties, particularly in social situations.
Women are especially likely to be overlooked because their experiences often do not match the stereotypes that shaped awareness of autism and ADHD for many years.
As awareness has improved, more adults have started recognising patterns that have been present throughout their lives.
For some, this brings relief.
For others, it raises new questions.
Either way, understanding these patterns can be an important step towards self-understanding.
Autism and ADHD Assessments at The Hummingbird Centre
The Hummingbird Centre provides autism assessments and ADHD assessments for children, adolescents, and adults across Newcastle, Lake Macquarie, Maitland, and surrounding areas, with telehealth options available for many clients across Australia.
Many people come to us unsure whether ADHD, autism, both conditions, or something else entirely may be contributing to their experiences.
A comprehensive assessment helps build a clearer picture so that support and recommendations are based on understanding rather than guesswork.
For many people, gaining that understanding is the beginning of a very different conversation with themselves. Instead of asking why they struggle, they begin to understand why they experience the world differently and what support may help them thrive.
