Summary
Is it ADHD, ASD or could it be both? We explore the differences and similarities between these neurodivergent conditions, and some of the experiences unique to people with both ADHD and autism (often known as AuDHD).
How Common are ADHD and Autism?
The adult prevalence (how many adults in the population are affected) of Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) may be affected by a number of factors:
1. Many adults were missed and never assessed as children.
2. Adult ADHD and autism services have long waiting lists for new assessments, which can limit access.
3. Diagnostic overshadowing means individuals can be missed if they have other mental health conditions that mask the symptoms of a neurodevelopmental condition.
The estimated prevalence of adult ADHD is 2.5-3.4%; this is more common than autism, which has an adult prevalence of 1-1.5%. Across large epidemiological studies it is estimated that 20-40% of adult with autism also have ADHD. Around 15-25% of adults with ADHD would also meet the diagnostic criteria for autism.
Understanding the differences is important because ADHD and autism can impact communication, relationships, work, school, emotions and sensory experiences in distinct ways. Furthermore, adults may have learnt to mask symptoms over time which can contribute to burnout and further challenges.
What is ADHD?
ADHD can manifest as difficulties with attention, motivation, hyperactivity/restlessness, impulse control and executive functioning. People with ADHD can hyperfocus on things they find interesting or enjoyable, but find it much harder to focus on boring tasks, or tasks that they find more challenging. It is also widely accepted that many people with ADHD experience more ups and downs in their emotions, and find it harder to regulate these. ADHD is usually broken down into three main components: inattention, hyperactivity and impulsivity. Some people will only have symptoms from one component, whilst others may have a mixture of all three.
Inattention
Distractible
Difficulty focusing
Challenges with organisation
Forgetful
Misplace belongings
Hyperactivity
Restlessness
Fidgeting
Excessive talking
Difficulty staying seated
Drive to move
Impulsivity
Interrupting others
Impulsive decision making
Blurting things out
Risk taking
Difficulty waiting
For people with ADHD the problem is not a lack of effort, in fact they are often trying harder than other people to function in daily life. The difficulties arise due to differences in their executive functioning and attention regulation. There are also strengths and benefits to having a neurodivergent mind. We all have areas we excel in and things we find more challenging. People with ADHD are often:
• Creative and innovative
• Good at generating ideas
• Highly adaptable and enjoy new experiences
• Enthusiastic with high energy levels
• Good under pressure
What is Autism or ASD?
Autism Spectrum Disorder (ASD) presents with differences in social communication, a preference for routine and repetitive behaviours, specific patterns of interests and differences in sensory processing of information.
Social Communication
Eye contact is uncomfortable
Dislikes small talk
Struggles to make friends
Finds socialising tiring
Interprets things literally
Routine and Repetition
Preference for routine
Distressed if plans change
Repetitive movements
Repeats words or phrases
Specific Interests
Intense and detailed knowledge of special interests
Collects items related to these
Interests tend not to change over time
Sensory Sensitivity
Strong aversion to light, sound, smell or texture.
Seeks sensory input e.g. swings or rollercoasters
Someone with autism may preplan conversations in advance, feel overwhelmed in noisy environments, prefer to talk at length about their special interests, favour a direct communication style or become upset if there is an unexpected change to plans. Similar to ADHD, people with ASD often have particular areas of strength:
• Ability to focus in depth on areas of interest
• Pattern recognition skills
• Strong moral compass
• Dependability – they do what they say they will do
• Strong memory for interests
• High attention to detail
Why might ADHD or ASD be missed?
It is widely recognised that screening tools and assessments were based on how these conditions presented in boys, and therefore do not represent presentations found in other groups, such as females. Individuals who are diagnosed with autism or ADHD in adulthood may have learned to mask their symptoms from a young age. Or they may have done well academically due to high levels of natural intelligence and therefore the challenges they faced were not identified at school. It may that their symptoms present when they go to university and the academic demands exceed their natural ability.
What is masking?
Masking is any behaviour that is adopted by a neurodivergent person to help them “fit in” with the people around them, thereby ‘masking’ their natural behaviours or preferences. Masking behaviours can include:
• Copying social behaviour and adapting your behaviour to the people you are with.
• Forcing eye contact or developing strategies for example looking at the bridge of someone’s nose.
• Pre-planning conversations.
• Actively trying to focus or force yourself not to interrupt.
• Concealing sensory distress or the desire to move by making excuses to leave the situation such as going to the toilet or filling up a water bottle.
• Becoming a perfectionist to limit errors.
• Relying on others such as a partner to provide structure and support.
Individuals who are academically successful, intelligent or appear sociable are more likely to present later for a diagnosis.
Burnout
When people with ADHD or ASD mask frequently or for a long time, they are more susceptible to burnout. This can present in the following ways:
ADHD
People with ADHD can struggle with executive dysfunction. Organisation and timekeeping are a constant challenge and the effort to manage these can lead to chronic overwhelm. People often feel a constant pressure to meet society’s expectations and experience a feeling of failure when they are unable meet the demands of daily life. This can lead to exhaustion and difficulty regulating emotions, which contributes to overwhelm and poor self esteem.
ASD
Autism burnout tends to be associated with prolonged masking and the accompanying social exhaustion. Many modern environments further contribute to sensory overload due to increased sensitivity to noise, light, texture and smell with little time to recover. People with ASD can find it harder to adapt to daily demands of life and last minute changes, which can lead to them feeling more anxious and overwhelmed.
What if you have ADHD and ASD (AuDHD)?
If you have both ADHD and autism this means that your symptoms fulfil the diagnostic criteria of both conditions. However, these experiences can also contradict each other.
Individuals may:
• Want to have a routine but struggle to maintain it.
• Want social connection but feel exhausted afterwards.
• Seek stimulation but then also become overstimulated.
• Want structure but also feel restricted by having a plan.
• Feel bored and want to experience new things but feel anxious about change.
When given the right environment they can often exhibit strengths across ADHD and ASD, such as high levels of creativity in subjects of interest, unusual problem-solving abilities with innovation and original ideas, high levels of curiosity and a desire for meaningful work.
Summary
From the outside ADHD and autism can present similarly; however they feel very different internally. If both occur together then there can be an internal struggle to balance the conflicting demands. For example, the desire for both new experiences and the safety of routine.
Establishing the correct diagnosis, especially for adults, can provide an explanation on why life has felt more exhausting, demanding and harder to manage when compared to the experiences of their peers or their expectations. Gaining understanding allows people access to support, helps them develop self-compassion and put strategies in place to support themselves. It also opens up the conversation with others in their lives to explain more about what support they might need.
If this article resonates with you or sounds like someone you know, then we can offer an assessment for ADHD, ASD or both conditions. All our assessments screen for mental health conditions and are delivered by consultant psychiatrists, either in person or online.
You can book your appointment here. We look forward to meeting you at The Mind and Psychiatry Clinic.
Sources
Simon, V. et al. (2009). Prevalence and correlates of adult ADHD: A meta-analysis. British Journal of Psychiatry, 194(3), 204–211.
Fayyad, J. et al. (2017). The descriptive epidemiology of DSM5 adult ADHD in the World Health Organization World Mental Health Surveys. Attention Deficit and Hyperactivity Disorders, 9, 47–65.
Brugha, T. et al. (2011). Epidemiology of Autism Spectrum Disorders in Adults in the Community in England.Archives of General Psychiatry, 68(5), 459–465.
Antshel, K. M., & Russo, N. (2019). Comorbidity of ADHD and ASD in adults: A clinical perspective. Current Psychiatry Reports, 21(10), 1–11.
National Institute for Health and Care Excellence (NICE). (2012, updated 2021). Autism spectrum disorder in adults: diagnosis and management (NICE Clinical Guideline CG142). London: NICE.
Dr Amy Martin is a consultant psychiatrist, and co-founder of The Mind & Psychiatry Clinic. She provides private psychiatric services in Edinburgh and via secure video consultation across the UK.
