ADHD and Autism

Attention deficit disorder and autism co-occur at high rates. They are both forms of innate neurodivergence. This means that they are genetic and can be present in childhood. They are similar. The overlap between them is poorly understood since the diagnosis manual we use as clinicians was released in 2013 when a clinician could not diagnose both ADHD and autism.

ADHD and autism can predispose people to personality disorders such as borderline personality disorder. A study done by Sokolova in 2017 on the co-occurrence of ADHD and Autism found that 30 to 65 percent of ADHD children have significant autistic traits. Sokolova estimated that 22 to 83 percent of autistic children meet the criteria for an ADHD diagnosis. Though these two diagnoses co-occur often, it is common to see elevated ADHD traits within autistics or more autistic traits in someone with ADHD. An individual can have significant trait overlap but not meet the criteria for both diagnoses.

ADHD and Autism impact how the brain processes sensory input and cognitive processes. They can impact executive functioning, attention processes, and sensory processing. Executive functioning difficulties are core components of ADHD and autism. Organizing tasks, object permanence, memory, focus, decision-making and regulating attention can be a difficult challenge when there is executive dysfunction. Social difficulties are common between ADHD and autism, but for different reasons. For ADHD, inattention or impulsivity can make it difficult to maintain attention in a conversation or social setting. For autistic people, it is related to difficulty picking up on social cues, understanding pretense, and body language intuitively. Autistic people may have difficulty switching from one task to another, social communication often involves considering multiple tasks at once.  Someone with autism may be more likely to struggle with back-and-forth conversation and use language repetitively or robotically. ADHD people are more susceptible to talking excessively, interrupting others, and not listening to what is being said in a conversation. Both lead to social dysfunction, but in different ways. Time blindness describes having an altered perception of time. ADHD and Autism often experience this phenomenon which is associated with interoception. Interoception is described as the 8th sensory system, it refers to the ability to sense internal signals. Signals associated with elimination, hunger, thirst, and emotions are all examples of interoception. It is integral to the ability to regulate emotions. a poor interoception is characterized with people having more difficulty registering and responding to their internal States and emotions as needed. ADHD and autistic people struggle with interoception at higher rates than the general public. For ADHD it could be considered that perhaps the difficulty with maintaining awareness of internal signals is due to poor attention regulation and difficulty focusing and therefore difficulty attending to interoception signals. Sensitivities to sensory input are common in both ADHD and autism. Both are related to how the brain processes that sensory input. Sensory sensitivities can be to clothing, food textures, or even feeling wetness on the skin. Repetitive movement, also called stemming, is commonly used to regulate among both autistic people and ADHD.

ADHD fidgeting can look like stimming in the context of autism. stemming could be rocking back and forth in a chair, tapping your foot, or clicking a pen. Centered around one’s passions and special interest is what the ADHD and autism community defines as hyper fixation and hyper focus or special interest. In ADHD hyper focus can look a lot like hyper fixation. A highly passionate individual with ADHD can look a lot like autistic special interest. Individuals with ADHD or autism have more sensitive amygdales. The brain circuitry, interoception issues, more rigid nervous systems and sensory processing can make emotional regulation more difficult for people with autism or ADHD. Difficulty regulating emotions can be associated with sensory meltdowns and sensory overload. These individuals also find difficulty soothing intense emotions when they occur. Rejection sensitive dysphoria, or RSD for short is a common experience for ADHD and autistic peoples. It’s hypothesized to be caused by increased difficulty in regulating emotions which leads to an abnormally heightened experience of rejection.  Because of the predisposed sensitivity to rejection, whether the rejection is real or imagined it can still create an extremely strong reaction in someone with neurodivergence who experiences this RSD.

How an individual responds to change is one of the things that distinguishes autism from ADHD.  To better understand the autistic experience, we must consider how the experience of self-initiated change versus change from an external source is seen differently. A person deciding to change their routine is one thing, but a forced or unexpected change is something else. In autism unexpected change that comes from the outside of us can cause intense anxiety, irritability and stress. In contrast the ADHD brain often seeks dopamine, excitement, and change versus how the autistic brain craves similarity, routine and repetition.

If you know or love someone with ADHD or autism, I encourage you to take to heart what you have read in the interest of being able to understand them more and extend compassion when needed. If this blog resonated with you, and you would like to speak with someone about your experiences or behaviors presenting in your life please contact Life Enhancement Counseling Services at 407-443-8862 to schedule an appointment with one of our licensed mental health counselors.






Arielle Teets