Why Is Dual Diagnosis for Autism and ADHD Missed?

PostedSeptember 17, 2025

UpdatedSeptember 17, 2025

ByMy Patient Advice

Author: Victoria Rowe, MSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

A missed dual diagnosis of AuDHD, the co-occurrence of autism and ADHD, is a common issue, and it can have a significant impact on individuals seeking appropriate support. Both autism and ADHD share overlapping symptoms such as inattention, impulsivity, and social difficulties, which makes it challenging for clinicians to distinguish between the two conditions. As a result, many individuals with ADHD and autism are not diagnosed with both conditions, often receiving only one diagnosis, which can lead to mismanagement of their symptoms.

The diagnostic challenges of identifying both autism and ADHD in an individual are partly due to the way these conditions present differently in various people. ADHD symptoms can be hidden by the social and communication difficulties linked to autism, and the same is true in reverse. This overlap can lead to comorbidity being missed during the evaluation process.
Key Reasons for Missed Dual Diagnosis

Here is why the dual diagnosis for autism and ADHD is often missed:

Overlapping Symptoms:

Autism and ADHD share many behavioural traits, such as difficulties with attention, impulsivity, and social interactions. A person with ADHD and autism may exhibit traits that could be attributed to one condition, but not both, leading to diagnostic challenges. For example, a child with ADHD may struggle to pay attention, but so might a child with autism, though for different reasons. This overlap can make it difficult to recognise when both conditions are present.

Gender Differences:

Autism and ADHD often present differently in males and females. In females, ADHD symptoms might be more subtle or masked by the social struggles typical of autism, leading to a missed dual diagnosis. Girls with AuDHD may show more internalised behaviours, such as anxiety or social withdrawal, which might be mistaken for other conditions, complicating the diagnosis further.

Lack of Awareness:

There is a lack of awareness around the possibility of ADHD and autism co-occurring. Many clinicians may not be trained to recognise both conditions in a single individual, especially if the symptoms are not immediately obvious or the person’s presentation doesn’t match the typical patterns for either ADHD or autism.

Addressing missed dual diagnosis of AuDHD requires clinicians to be more aware of how ADHD and autism can manifest together and to use more comprehensive diagnostic tools that evaluate both conditions simultaneously. Early recognition and intervention can lead to more effective treatment and a better quality of life for individuals with AuDHD.

Visit providers like ADHD Certify for personal consultations to ensure that both ADHD and autism are properly diagnosed and addressed.

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to Autism Spectrum Disorder.

Victoria Rowe, MSc

Author

Victoria Rowe is a health psychologist with a Master’s in Health Psychology and a BS in Applied Psychology. She has experience as a school psychologist, conducting behavioural assessments, developing individualized education plans (IEPs), and supporting children’s mental health. Dr. Rowe has contributed to peer-reviewed research on mental health, including studies on anxiety disorders and the impact of COVID-19 on healthcare systems. Skilled in SPSS, Minitab, and academic writing, she is committed to advancing psychological knowledge and promoting well-being through evidence-based practice.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy.

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.