The Similarities and Differences Between Autism & ADHD

ADHD and autism are often seen as interchangeable terms; they have overlapping symptoms, shared neurological roots, and can often be misdiagnosed as one another. Additionally, they are often comorbid – as much as 70% of the autistic population have ADHD in addition to autism.

These factors make it challenging to distinguish between autism and ADHD. However, understanding the differences between the two is crucial not just for an accurate diagnosis, but also to ensure that friends and family around you who may be suffering from either of these disorders are given the support they need, This blog will give you an overview of ADHD and autism, their respective symptoms, and their neurological origins.

What is Autism?

Generally speaking, autism – or ASD, the abbreviation of Autism Spectrum Disorder – is a developmental disorder that can lead to difficulties interacting socially, repetitive behaviors, and restricted interests. These can be incredibly varied across the spectrum of autistic experiences; for instance, some autistic people can have trouble making eye contact, whereas others may make excessive eye contact. This is due to differences in masking levels. For instance, autistic people who aren't masking as much might not make as much eye contact due to their discomfort with it. On the other hand, when autistic people mask more, they may make more eye contact to overcompensate for their discomfort with eye contact.

Despite these potential differences in the symptoms of autism, most autistic people experience some variety of differences in communication. These can include not appearing to pay attention to conversation, having difficulty relating to people on a personal level, and even having a strange tone of voice. All of these symptoms can make it difficult for autistic people to function in a neurotypical society, as communication with neurotypical people is often essential. Because of this, autism can result in social isolation.

Symptoms of Autism

Finding it hard to understand what others are thinking or feeling
Getting very anxious about social situations
Finding it hard to make friends or preferring to be on your own
Seeming blunt, rude, or not interested in others without meaning to
Finding it hard to say how you feel
Taking things very literally – for example, you may not understand sarcasm or phrases like "break a leg"
Having the same routine every day and getting very anxious if it changes
Not understanding social "rules" such as not talking over people
Avoiding eye contact
Getting too close to other people or getting very upset if someone touches or gets too close to you
Noticing small details, patterns, smells or sounds that others do not
Having a very keen interest in certain subjects or activities
Liking to plan things carefully before doing them

The Positives and Negatives of Autism

The effects of autism include many things that can have potentially negative and positive impacts on the lives of autistic people. For instance, a common effect of autism is difficulty in processing. 'Processing' can include everything from perceiving the space around one, understanding emotions and expectations in other people, and being able to communicate in ways that are stereotypically considered 'appropriate' (which includes things like knowing when to use sarcasm). Additionally, autism can lead to complications in mental health; for many people, autism can result in anxiety and/or depression.

Despite these things, autism can have many positives. For instance, many autistic people will have incredible abilities in areas of specific interest, such as art, writing, music, and mathematics. This can also extend to incredible abilities in remembering and perceiving things around one - such as facts about things one is interested in or how puzzle pieces should fit together.

The Science Behind Autism

There isn't much known about what brain changes lead to autism; most of what is known in scientific fields is that autism is largely caused by genetic factors. Though we do not yet understand those factors, they contribute a huge portion to how likely one is to have autism.

Aside from genetic factors, one of the major causes of autism is thought to be changes in the size of minicolumns. In essence, minicolumns are incredibly tiny columns of neurons with similar properties that go into the surface of the brain. Many autistic people have been found to have more and thinner minicolumns than average. This change is thought to lead to sensory sensitivities and more bias toward low-level processing, or understanding surface-level qualities of one's environment

ID: A man and a woman sit next to one another, one of them reading from a book and the other taking notes. They smile as they work.

What is ADHD?

ADHD is a neurodevelopmental disorder that affects executive functioning, or the ability to organize and complete tasks promptly. Effects of ADHD can include difficulty with starting tasks, having trouble finishing time-consuming tasks, and being easily distracted while at work. These things can lead to struggles in the workplace or at school.

Like autism, the effects of ADHD can change depending on the level of masking. For instance, some people with ADHD will have few difficulties completing work until high school or even college, while others will have trouble completing tasks as early as elementary school. These differences in effects can lead many people with ADHD not to get the help they need when they need it and is a massive part of why ADHD can be mis- or undiagnosed.

Symptoms of ADHD

Having a short attention span and being easily distracted
Making careless mistakes – for example, in schoolwork
Appearing forgetful or losing things
Being unable to stick to tasks that are tedious or time-consuming
Appearing to be unable to listen to or carry out instructions
Constantly changing activity or task
Having difficulty organizing tasks
Being unable to sit still, especially in calm or quiet surroundings
Constantly fidgeting
Being unable to concentrate on tasks
Excessive physical movement
Excessive talking
Being unable to wait their turn
Acting without thinking
Interrupting conversations
Little or no sense of danger

The Positives and Negatives of ADHD

ADHD can affect one's life in many positive and negative ways. For instance, people with ADHD are more likely to fall into dangerous patterns of behavior, such as excessive drinking and drug use. People with ADHD also often have difficulties in relationships, as ADHD can lead many people to react differently from what is considered normal in certain situations, and people with ADHD can have trouble controlling their emotions. ADHD also has a high comorbidity with anxiety and depression, which can be due to difficulty interacting with others.

However, there are many positives to living with ADHD. For instance, people with ADHD can have incredible creativity and are often inclined to think outside of the box. Additionally, people with ADHD are often known for being incredibly resilient, as working with your brain when you have ADHD can be incredibly difficult, and moving past this requires great resilience.

The Science Behind ADHD

Neuroscientists have found many potential connections between different sections of the brain and ADHD. One of the most significant connections, however, is in chemistry: it's related to two brain chemicals, dopamine and norepinephrine. To simplify, your brain wants to make dopamine into norepinephrine because norepinephrine is a reward (specifically for doing tasks that help you survive, but that's not hugely relevant here). However, the only way for dopamine to become norepinephrine is if it's taken in transporters to a different section of the brain. This relates to ADHD because people with ADHD don't have as many transporters, which means that their brains can't create norepinephrine as easily. Neuroscientists currently hypothesize that this is one of the causes of inattention and impulsivity in ADHD.

Similarities and Differences

Difficulty Interacting Socially

One commonality between ADHD and autism is difficulty in interacting with others. This can manifest in many ways, such as having trouble keeping eye contact, struggling to communicate in a way that's considered 'normal', and struggling not to interrupt a conversation. For both conditions, this can be drawn back to difficulties in understanding how to communicate with others in a neurotypical manner. However, specific differences in communication methods exist between ADHD and autism - for instance, where an autistic person might find it difficult to inflect the right tone of voice, a person with ADHD may have difficulty in listening attentively to others. Regardless, these methods of communication can lead to difficulty in establishing relationships in both people with ADHD and autistic people.

Fidgeting/Self-Stimulating Behaviors

People with ADHD and autistic people also share an affinity for self-stimulating behaviors or stims. To people looking on, these may appear to be simple ways of fidgeting, but in reality, they are a way many neurodivergent people control the level of stimulation they are experiencing so that it can be manageable. For instance, someone with ADHD might fidget with a pencil while they're working to increase their level of stimulation and keep themself engaged. On the contrary, someone with autism might hum to themself if they're in a loud room to give themself something to focus on and control outside of the overstimulating environment they're in. Though these behaviors can differentiate from person to person, they are always useful tools for autistic people and people with ADHD to get through their days.

Differences in Processing

Both ADHD and autism involve differences in processing which can make it difficult for them to function in a neurotypical world. For instance, autistic people will often have difficulties processing things in social situations to inform the 'correct' way for them to act. On the contrary, people with ADHD can often have trouble processing the information they need to understand a situation, which can manifest in terms of things like lack of concentration and can lead to impulsive behaviors. Both autistic people and people with ADHD can have difficulties with processing sensory information, which can lead to sensory overwhelm. Despite this similarity, the differences in processing that result from ADHD and autism can have very different results depending on which type of neurodiversity one falls under and how one experiences it.

Conclusion

In short, autism and ADHD have a great number of similarities between them that can sometimes make it difficult to distinguish between them. Fortunately, there are many differences between ADHD and autism that can make telling the difference between them relatively simple.

It's vital to know about these distinctions because they can help you better understand what people with autism and ADHD are struggling with and how better to support them through it. Additionally, it makes it far more difficult for you to make assumptions about people with ADHD and autistic people. This allows you to become someone that people with either one trust to understand their difficulties, which is essential as not all neurodivergent people get this kind of support.

If this blog has led you to consider whether you have ADHD or autism, you may want to speak to a therapist. They have experience determining what autism or ADHD looks like in an actual person, and even if you already have that experience, they can give you a trustable perspective on whether your concerns are justified. Additionally, if you find out you have either condition or if you already know you have one or the other, a therapist can help you learn more about yourself and find a path to masking less.

Trust Mental Health has an incredible base of therapists who are positioned to help you with either one of these things, or even both. With Trust Mental Health, your therapy works with your preferences - for instance, you can have your therapy sessions in one of 18 different languages and you have a choice between online and in-person sessions. Trust Mental Health also has therapists from a variety of different backgrounds so you can speak with someone you know will understand your struggles.

3 Key Points:

Common symptoms of autism include difficulty in social situations, a need for routine, and a higher ability to notice things that others don't
Common symptoms of ADHD include difficulty focusing, increased forgetfulness, and impulsive behaviors
Though autism and ADHD might seem to present very similarly, there are many subtle differences between them.

FAQs:

How do you know if you have ADHD and/or autism?

Understanding whether you have autism or ADHD is something that doesn't have a set path. A good place to start, however, is looking for a symptom list; from there, you can determine whether or not the diagnosis fits with your experiences thus far. Determining this may take some time, as it's important to ensure you're not misdiagnosing yourself, and that can often take a huge amount of self-reflection. If you're feeling relatively confident in your self-diagnosis, you might want to start asking the people around you if they believe you might have ADHD/autism. If you and the people around you agree that it's likely, you may want to look into getting a diagnosis.

In all of the steps, having a therapist to talk to about whether or not autism or ADHD seems to align with your experiences can be incredibly helpful.

How do you get diagnosed with autism or ADHD?

Once you are almost completely certain you have ADHD or autism, you may want to get a diagnosis. One of the best ways to start this process is by going to talk to a professional about why you think you should be diagnosed. It may be helpful to come to this meeting prepared with a written list of symptoms that you experience and even notes from other people about what symptoms they've noticed in you. After that, you'll need to find a person or organization you trust to get you your diagnosis. From that point on, you simply need to complete an evaluation to determine whether you have autism or ADHD.

Here is a more in-depth source of information for ADHD, and here is one for autism.

I have friends/family who have ADHD and/or autism. How can I best support them?

The most important way you can support someone with autism or ADHD is to listen to what they're struggling with and help if you have that ability. For instance, if your friend is feeling overwhelmed by their environment, see if you can help them move to a quieter, less visually stimulating area. Helping out might also include allowing your friend or family member to borrow something to fidget with if they begin to feel understimulated.

Additionally, make sure you show your family member or friend with ADHD or autism that you respect them for who they are. This allows them to be themselves around you, which is vital for them to live a happy and fulfilling life.

THE TRUST MENTAL HEALTH CARE TEAMJanuary 15, 2025