April 4, 2025 - neurocare group
Recent years have seen more people diagnosed with co-occurring Attention Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD), leading to the birth of a popular term: "AuDHD". Historically, co-presenting ADHD and ASD were underdiagnosed, but new diagnostic changes and finer assessment techniques are improving diagnostic accuracy. What does this mean for patients?
Changes in Diagnostic Criteria
The Diagnostic and Statistical Manual of Mental Disorders (DSM), used by healthcare professionals to evaluate and diagnose mental health conditions, plays a major role in how we understand neurodevelopmental disorders like ADHD and ASD. Before 2013, when the DSM-5 was released, professionals were unable to diagnose both ADHD and ASD in the same individual. This was because older versions of the DSM listed them as mutually exclusive conditions - you couldn't have ADHD if you had ASD, and vice versa.
However, the introduction of the DSM-5 provided a critical update. Clinicians can now officially diagnose both ADHD and ASD in the same individual, recognizing that these two conditions often present together, rather than being separate or competing for diagnostic priority. This is the main reason for the rise of co-diagnoses, or the increase in "AuDHD". Since the DSM-5 revision, professionals are increasingly diagnosing individuals with both conditions, better reflecting the complexity of neurodiversity.
Symptom Overlap and Misdiagnosis
In addition to DSM classification changes, an important reason for the historical underdiagnosis of ADHD and ASD is the similarity in symptoms between them. Both conditions share many features such as impulsivity, difficulties with focus, executive functioning challenges, and emotional dysregulation. Individuals with both conditions may experience a wide variety of behaviours or symptoms, and overlapping symptoms often occur for different reasons in each condition.
The similarity of symptoms between ADHD and ASD can lead to one diagnosis overshadowing the other. For instance, a child might receive a diagnosis of ADHD due to their hyperactivity, while their ASD traits go unnoticed because they are less pronounced or are mistakenly attributed to their ADHD. This is why the DSM-4 disallowed dual diagnosis. Similarly, some individuals are diagnosed with ASD, but their inattention or impulsive behaviour might be misinterpreted as part of their autism rather than signs of ADHD. In practice, these things can be difficult to separate in some cases, but with greater awareness and more refined diagnostic tools, more professionals are now able to deliver accurate results more often.
Genetic and Neurobiological Factors
There are neurobiological underpinnings of both ADHD and ASD, suggesting that the two disorders share common pathways. Studies have found a significant genetic overlap, which means that certain genetic factors can predispose individuals to develop both ADHD and ASD. Neurobiologically, both conditions impact a lot of the same areas of the brain involved in executive functioning, such as organization, planning, and impulse control. Notably though, a person's environment and living conditions can impact ASD and ADHD symptoms as much as, or even more than genetic factors.
Subjectivity
People with ASD and ADHD can have a wide range of symptoms and experiences. Just knowing that someone has an ADHD diagnosis provides limited insight into their unique experience, as they could have any combination of a broad spectrum of symptoms and behaviors. For instance, they might feel uncomfortable in large groups or small groups, prefer noisy or quiet environments, enjoy studying or dislike it, or none of those.
ASD is similar - people with ASD often have very different experiences to each other. When presenting together, ASD and ADHD can interact with each other in new ways as well. For these reasons, each person with "auDHD" could have very different symptoms.
Assessments for ADHD and ASD must consider these individual differences. In practice, clinicians are able to create individualised assessments by combining specific tests for symptoms a person is experiencing. By doing this, the clinician can make sure an assessment yields useful results for a person without providing too much confusing information or needlessly increasing cost.
The Internet and "auDHD" mental health awareness
Social media platforms and forums have empowered people to share their experiences and identify symptoms they have in common, which has encouraged many to seek professional help. As terms like "auDHD" are used more often, people who previously may have gone undiagnosed are now recognizing their symptoms in descriptions from other people, leading them to pursue formal assessments. This is a great thing, most of the time.
However, online forums can be very unreliable and do damage in some cases. Online perceptions usually don't match what a clinician would say, and coping strategies that one person finds helpful might be destructive for someone else - particularly when people with the same diagnoses present very differently like with ADHD and ASD. It is critical to seek professional opinions and take them more seriously than what is available online.
While the term "AuDHD" is not a formal diagnosis in the DSM, it has been adopted by many to describe the unique experience of living with both ADHD and autism. In professional practice, ADHD and ASD are different disorders and are assessed independently. Everyone is different, so it is important that both ADHD and ASD are assessed using tailored and standardised assessments.
Finding Support
With so much information available online, finding support can be overwhelming. ADHD and ASD should both be assessed using individualised, standardised techniques in clinical settings. This will maximise the chance of an accurate diagnosis and allow your clinician to provide more helpful and relevant feedback than online.
At neurocare, we specialise in individualised assessments for ADHD and related disorders. We also provide individualised, multidisciplinary treatment programs tailored to each individual's unique experience. To find out more, click the link below.
