How Autism, ADHD and Trauma Overlap in Adults – And How to Find Support for AuADHD

Understanding AuADHD in Adults: When Autism and ADHD Co-Occur

Many adults live for decades without knowing they are neurodivergent. For some, the answer only emerges when they explore adult ADHD symptoms, or begin to question whether they might be autistic. For others, the true picture becomes clear when both are diagnosed. This co-occurrence of autism and ADHD in adults is now widely recognised and is often referred to as AuADHD.

Living with both conditions brings unique challenges. It often leads to missed diagnoses, internal conflicts, and mental health issues rooted in unrecognised trauma. Recent books and experts—including Leanne Maskell, author of ADHD: An A to Z, and Dr Khurram Sadiq, consultant psychiatrist and advocate for adult ADHD diagnosis—are helping to shift the conversation toward better understanding and support for this overlooked population.

This article offers a detailed guide to AuADHD in adults, a checklist of common traits, and an exploration of how autism and ADHD can clash. It is written to support those seeking clarity, validation and trauma-informed care from a neurodiversity-affirming therapist.

What Is AuADHD?

AuADHD describes individuals who meet diagnostic criteria for both Autism Spectrum Condition and Attention Deficit Hyperactivity Disorder. Research now suggests that between 30 to 80% of autistic individuals also meet criteria for ADHD, and vice versa.

While the DSM-5 (2013) finally allowed for dual diagnoses, clinical services and public understanding have lagged behind. Many adults receive only one diagnosis or are mislabelled entirely. In the UK, late diagnosis of autism and undiagnosed ADHD often contribute to feelings of shame, exhaustion and self-blame, especially for those who have been masking since childhood.

How AuADHD Presents in Adults

According to Dr Khurram Sadiq, adults with co-occurring autism and ADHD are often misdiagnosed with anxiety or emotionally unstable personality disorder. This is particularly common when trauma is also present, which can further obscure the underlying neurodivergence.

Leanne Maskell describes her own experience of ADHD in adulthood as a mix of chaos and brilliance, often misunderstood by those around her. When autism is also part of the picture, the internal landscape becomes even more complex. The adult may appear high-functioning but be experiencing regular autistic burnout and executive dysfunction.

Common patterns in adults with AuADHD:

Constant conflict between needing routine and craving novelty
Difficulty regulating attention, emotions and sensory input
Perfectionism rooted in trauma from rejection or exclusion
Fatigue from masking autistic traits or impulsivity
Struggles with executive functioning like planning, organising and decision-making

Checklist: AuADHD Traits in Adults

This checklist combines clinical research with lived experience. It can be a useful tool for those wondering whether ADHD or autism traits in adults resonate with their own experience.

Focus and Attention

Difficulty maintaining attention unless hyperfocused
Forgetting what was just said during conversations
Struggling with repetitive tasks and boredom
Starting many projects, finishing few

Executive Functioning and Organisation

Chronic lateness and poor time management
Losing important items like keys or paperwork
Forgetting daily responsibilities
Difficulty transitioning between tasks or roles

Sensory Processing and Overload

Sensitivity to lights, sounds, touch or smell
Shutting down in busy environments
Needing repetitive routines or sensory comforts
Using movement or fidgeting to self-regulate

Social and Emotional Regulation

Masking autistic traits to “fit in”
Intense emotional reactions to perceived rejection
Difficulty maintaining long-term friendships
Overanalysing social interactions

Identity and Trauma Responses

Strong inner critic or feelings of being ‘too much’
History of developmental or relational trauma
Burnout from overcompensating for internal difficulties
Oscillating between people-pleasing and withdrawal

When ADHD and Autism Clash in Adults

A hallmark of AuADHD is internal contradiction. ADHD traits may push someone toward risk-taking or social novelty, while autistic traits create a need for routine and predictability. This creates tension, confusion and sometimes emotional shutdowns.

1. Structure vs Impulsivity

Autistic parts of the brain seek routine and consistency. ADHD traits lead to procrastination, last-minute decisions and novelty-seeking. This makes daily life difficult to plan or sustain, and often leads to feelings of failure.

2. Social Craving vs Social Exhaustion

ADHD may drive someone to engage socially, while autistic traits cause rapid sensory fatigue and difficulty with eye contact or unspoken rules. The person may mask their discomfort, leading to post-event emotional collapse.

3. Stimulus Seeking vs Sensory Overwhelm

ADHD often seeks stimulation like movement, loud music or multi-tasking. Autism often avoids these same stimuli. The result is a nervous system constantly caught between ‘too much’ and ‘not enough’.

4. Emotional Intensity vs Shutdown

ADHD traits express emotion outwardly—excitement, frustration, anger—while autistic traits often suppress emotional expression. This can lead to confusion in relationships and misinterpretation by others.

How Trauma Impacts AuADHD Adults

Many adults with AuADHD carry a history of trauma from being misunderstood, excluded or punished for their neurodivergent behaviours. Childhood experiences of being told they were lazy, rude, or disruptive can form deep-rooted beliefs about being “too much” or “not enough”.

Therapeutic work must address these internalised beliefs. Trauma-informed therapy for ADHD and autism includes:

EMDR Therapy to process memories of shame or rejection
IFS Therapy to work with parts that developed to protect against pain
Neurodiversity-affirming coaching to support executive function and self-trust
Psychoeducation on autism and ADHD in adulthood to reduce self-blame

Moving Towards Healing and Understanding

Adults with AuADHD deserve recognition, validation and support. Diagnosis is often the start of healing—not because something is wrong, but because it finally explains years of difficulty. Understanding your neurodivergent brain helps reduce shame and leads to more compassionate strategies.

As Leanne Maskell writes, “We don’t need to be fixed. We need to be understood.”

Key Takeaways:

AuADHD is a common but under-recognised profile of neurodivergence
Symptoms often clash, creating internal stress and misunderstood behaviours
Trauma is common in adults who were undiagnosed or unsupported
Therapy works best when it is trauma-informed and neurodiversity-affirming

Get Support for AuADHD, ADHD and Autism in Adulthood

If you’re looking for therapeutic support that understands the overlap between autism, ADHD and trauma, visit philipbrucetherapy.co.uk.

I offer IFS therapy, EMDR, and trauma-informed psychological support for adults exploring their neurodivergent identity. Whether you are newly diagnosed, suspect you may be AuADHD, or feel overwhelmed by conflicting parts of yourself—help is available. life, I invite you to contact me for a consultation. Together, we can explore how Schema Therapy can help you reshape your deep-rooted patterns and achieve lasting change. of safety, trust, and hope. whether this approach could be right for you.