What’s the Difference Between ADHD and Autism? Here’s How to Tell Them Apart

ADHD and autism have been thought of as entirely distinct neurodivergent conditions for a long time. It’s true that they are different – but they’re more similar than scientists and psychologists previously thought. While the two don’t necessarily look the same on paper, the truth is that they often share overlapping symptoms. 

As a therapist who specializes in ADHD, I do see some overlap with my clients. So what’s the difference between ADHD and autism – and how do you know whether you have one, the other, or both? Let’s take a look. 

ADHD and Autism Similarities and Differences

ADHD is characterized by a broad range of symptoms that include inattention (struggling to concentrate and focus), impulsivity (lack of self-control), or a combination of both.

While someone with ADHD can have primarily inattentive-type or primarily impulsive-type, everyone with ADHD shares difficulty with executive functioning. These are a set of skills that allow you to be well organized, manage time well, and recall things properly.

ADHD looks different from person to person, and may vary throughout your life. Here are several ADHD and autism similarities and differences. 

Signs of ADHD in adulthood can include:

• Difficulty focusing or prioritizing tasks
• Losing and misplacing items
• Having several ongoing projects at once
• Forgetfulness
• Restlessness, edginess, or impatience
• Speaking over or interrupting others
• Difficulty with self-restraint or self-control
• Difficulty managing your emotions
• Anxiety and/or depression
• Easily overwhelmed by stress
• Easily overwhelmed by sensory stimulation
• Engaging in risky behaviors, such as unsafe driving or unsafe sexual practices

Autism is characterized by things like speech delays or difficulties, differences in social capacity, repetitive body-based behaviors, and sensitivity to stimulation. 

Signs of autism in adults can include:

• Inability to interpret social cues
• Difficulty understanding what others are thinking or feeling
• Anxiety, especially about social situations or changes in routine
• Difficulty maintaining friendships or relationships
• Difficulty understanding sarcasm or jokes
• Speaking over or interrupting others
• Unintentionally coming across as blunt or rude to others
• Difficulty with social interactions that include physical touch, eye contact, or lots of people in a small space
• Difficulty managing or communicating your emotions
• Easily overwhelmed by stress
• Easily overwhelmed by sensory stimulation

While each condition has distinct signs and symptoms among adults, there are some clear similarities. Being overwhelmed by sensory stimulation, experiencing anxiety, and having a hard time in certain social contexts are some shared signs. 

Autism and ADHD: Overlapping and Discriminating Symptoms

While autism and ADHD may not have many overlapping symptoms on paper, the reality is that these two conditions share many similarities. Here are 5 overlapping symptoms. 

1. Both form as a result of neurodivergence.

Neurodivergence is a trait of someone whose brain has developed differently from a typical brain. This type of differing neurological development in the brain is just one normal and expected way people are different from one another.

Neurodivergent people have different strengths and challenges from neurotypical people. For example, someone with ADHD may struggle to focus on a seemingly simple task, but they may excel at researching something when it’s of interest to them. Similarly, someone with autism may struggle to make small talk with others, but may have an impressive range of knowledge about a topic they love. 

2. Both exist on a spectrum.

Neurodivergence is a spectrum.

There are plenty of stereotypes in place that make it seem like ADHD or autism can only look one way. Think: the boy in the classroom who can’t sit still and fidgets throughout the school day. Or the girl with a flat affect who starts to yell if someone touches her plate. 

These stereotypes can be harmful in many ways. For one thing, they paint a picture of neurodivergence as inherently wrong, bad, dangerous, or weird. They also keep many people from finding effective treatment, because so many neurodivergent folks don’t recognize themselves in the stereotypes. 

Furthermore, your ADHD or autism may be more or less severe or disruptive to your life than a friend’s, and that’s okay. Everybody is different, and has differing needs and struggles. These needs and struggles often vary day by day, and that’s okay too. 

3. Both can make engaging with other people difficult.

Many people with ADHD and autism experience social anxiety and can struggle to maintain healthy relationships. However, the reasons for each may be different.

If you have ADHD, you may recognize your own inability to control your impulses when it comes to interrupting others or speaking out of turn. This can make socializing harder and more fraught.

If you have autism, you might worry that you won’t be able to pick up on subtle body language or social cues. This will likely increase your anxiety in social settings as well. 

4. Both include environmental sensitivity.

People with autism or ADHD (or both) tend to be more sensitive to environmental stimulation. They may become more easily overwhelmed in everyday settings than neurotypical people. 

5. Both often involve difficulty managing one’s own emotions.

ADHD and autism can both involve irritability, frustration, impatience, and mood swings. These emotional highs and lows often feel involuntary and can be difficult to manage.

This is sometimes due to executive dysfunction and the frustrations that come along with it. It may also be due to sudden internal or external overwhelm. Either way, big shifts in a neurodivergent person’s brain or environment can lead to mood swings, anxiety, and “shoulding” yourself. 

Low-support Needs Autism and ADHD in Adults

Many people who have autism or ADHD or both have found numerous coping tools throughout their lives to help them navigate their neurodivergence.

Women, for example, tend to “hide” their symptoms of both autism and ADHD more than men do. Adults of any gender may do this, particularly if they’ve struggled with symptoms of either condition since childhood. 

This is a phenomenon called masking. And low-support needs autism and ADHD in adults often involves masking.

If you mask your symptoms, you may do things like:

• Copy the behaviors of neurotypical people around you in order to fit in better
• Tamp down your feelings and anxieties
• Navigate social situations with apparent ease (despite feeling like a wreck inside)
• Learn to hide things like repetitive behaviors
• Pretend to be more engaged or at ease around others than you feel

Masking is often an incredibly useful way for a neurodivergent person to navigate a neurotypical world. Low-support needs autism and ADHD in adults often calls for behaviors like these in order to get through life.

Unfortunately, masking also comes with drawbacks. By hiding your feelings and constantly pretending to be someone you’re not in order to fit in, you’re essentially sending yourself the message that you’re not good enough as you are. Or that you need to change in order to be loved and accepted.

Therapy and Coaching Can Help You Learn the Difference Between ADHD and Autism

If you’re neurodivergent and want support navigating the ADHD and autism similarities and differences, I'm here to help.

I work specifically with people with ADHD and am here to help you navigate ADHD successfully in adulthood. That includes figuring out what it looks like for you, setting goals to improve your relationship to your neurodivergence, and working through your challenges together. 

Our work together will help you feel empowered and confident, knowing you have the skills and tools to better understand your behaviors and drives.

I’m ready if you are. Reach out today to get started.