What are the symptoms of ADHD and autism, and why do they often overlap?
When we talk about autism and ADHD (attention deficit hyperactivity disorder), we are not only exploring two different conditions but also a complex terrain where they are often intertwined. This overlap can be confusing for families, educators, and even healthcare professionals, as both disorders share specific symptoms. In fact, it wasn’t until 2013 that the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) allowed for the dual diagnosis of autism and ADHD. So, what are the symptoms of ADHD and autism, and why do they often overlap?
To answer this question, we must first understand each condition separately and then explore why they may overlap in specific characteristics. Neurodevelopmental experts have found that there are high rates of children with autism who have ADHD and vice versa. Although autism spectrum disorder (ASD) is related to deficits in social and communication skills and ADHD to problems concentrating, their neurological and biological explanation may have many commonalities.
Throughout this blog by ABA Centers of New Jersey, you will find clear answers, practical examples, and resources that can help you better understand the relationship between autism and ADHD.
1. Explaining Autism Spectrum Disorder (ASD)
ASD is a neurological and developmental condition that affects how people perceive the world and socialize with other individuals. Although it varies from person to person, some common symptoms of autism include:
- Difficulties in communication and social interaction: For example, a child may avoid eye contact or need help understanding sarcasm or jokes.
- Repetitive behaviors or intense interests: This symptom may include a desire to line up toys in a certain way or develop a deep interest in a specific subject, such as trains or dinosaurs.
- Sensory sensitivity: Many individuals with ASD can feel overwhelmed with particular sounds, textures, or lights.
It is important to note that autism is not a disease but a different way of experiencing the world.
Specialists usually diagnose autism in early childhood, and the severity of its symptoms can vary, hence the term “spectrum.” Although there is no “cure” for autism, there are scientifically supported therapeutic methodologies, such as Applied Behavioral Analysis or ABA therapy, that can help individuals with ASD learn essential skills that allow them to participate in the community and gain independence.
2. Understanding Attention Deficit Hyperactivity Disorder (ADHD)
ADHD, on the other hand, as defined by the National Institutes of Health (NIH), is characterized by persistent patterns of inattention, hyperactivity, and impulsivity that interfere with daily life. Some of the symptoms of ADHD include:
- Difficulty concentrating: Children with ADHD may seem distracted even in activities they enjoy, often having difficulty organizing tasks and following directions.
- Impulsivity: This symptom may manifest as talking out of turn or difficulty waiting in line. Individuals with ADHD also tend to make rash decisions and often react immediately.
- Hyperactivity: Individuals can exhibit this behavior as the need to be “always on the go,” such as running around the room for no apparent reason. It can also be seen as constant restlessness and difficulty performing quiet tasks.
ADHD affects not only learning but also interpersonal relationships and self-esteem. Specialists may diagnose ADHD during childhood, and it may persist into adulthood, although the symptoms of ADHD may manifest differently in adulthood.
3. Coinciding Symptoms and Traits of Autism and ADHD
Autism and ADHD share several traits and are two conditions that can present at the same time. The European Child & Adolescent Psychiatry estimates that about 20-50% of children with ADHD also meet diagnostic criteria for autism, and 30-80% of children with ASD also possess diagnostic features of ADHD.
Overlapping symptoms of autism and ADHD may include:
- Difficulty sustaining attention: Children with autism and ADHD may appear “disengaged” or distracted. Although attention challenges are often a significant feature of individuals with ADHD, some children with autism may also face difficulty sustaining attention, especially when the context is not of interest to them.
- Difficulties in social interaction: Individuals with both ADHD and ASD may present challenges in understanding social cues and maintaining relationships. However, their manifestations in each condition vary.
- Impulsivity and Restlessness: This trait may appear in both conditions, although in autism, it may be more related to an intense desire to follow routines, elopement behaviors, and stimming, which involves repetitive movements.
- Problems regulating emotions: Children with either of these conditions may have emotional outbursts or difficulties handling frustration.
- Difficulties in executive functioning: Executive functioning refers to the cognitive abilities that allow planning, organizing, prioritizing, maintaining tasks, regulating emotions, time management, problem-solving, and decision-making. These mental processes can be problematic for people with autism and ADHD.
Autism vs. ADHD: The Key Differences
Although they share symptoms, their origins, traits, and management approaches are different. When comparing autism vs. ADHD, we must keep in mind these crucial differences to obtain an accurate diagnosis and access appropriate intervention strategies. The critical differences between autism and ADHD are:
- Social Difficulties: In autism, the problems in interaction are more profound and are related to understanding social norms and reciprocity. In ADHD, although children may exhibit difficulties in social skills, these challenges are typically secondary to attention and executive function.
- Repetitive Behaviors and Restricted Interests: One of the core features of ASD is repetitive behaviors and restricted interests, whereas this symptom is not definitive for ADHD. Individuals with autism exhibit these traits as intense preoccupation with specific topics, generalized anxiety, rigidity in following routines or rituals, and sensory sensitivities. On the other hand, individuals with ADHD may quickly jump from one topic to another in conversations or daily activities.
- Cognitive Profile: Archives of Clinical Neuropsychology analyzed the results of cognitive tests on more than 1,800 people with autism and ADHD to understand better how their minds work. They found that individuals with autism have a mental profile that can be “patchy”: they are good at verbal and nonverbal reasoning (problem-solving and understanding skills) but tend to be slower at processing information and have a slightly weaker working memory.
On the other hand, people with ADHD do not show such a marked profile. Their performance is generally in line with what is expected for their age, although they also have a slightly lower working memory.
- Therapeutic Approach: Although there are several behaviorally based therapeutic interventions for ADHD, many specialists recommend medication. Physicians prescribe stimulants such as methylphenidate and amphetamines to control inattention, hyperactivity, and impulsivity. These drugs balance neurotransmitters, mainly dopamine and norepinephrine. In contrast, with autism, the primary therapy focuses on a behavioral approach, such as ABA therapy. This approach is more common and effective in treating the more complex symptoms of ASD.
5. Autism vs ADHD: Why do They Look Alike and Often Overlap?
Researchers are still trying to understand why ADHD and autism have so many similarities and often occur together. While there are no definitive answers, there are some theories that bring us a little closer to the answer:
- Shared Genes: ADHD and autism have a significant genetic basis. Both conditions can be linked to genes that affect how the brain develops, how neurotransmitters (the chemicals that transmit signals in the brain) work, and how neurons connect. For example, some of these genes affect the production of dopamine (DRD4) and molecules that help neurons “cling” to each other (NRXN1). These shared genes could explain why there are similar symptoms and why both disorders often occur at the same time.
- Differences in the Brain: Studies using brain imaging, such as MRI scans, have found that people with autism and ADHD have brain connections that work differently. These differences can affect areas responsible for attention, social skills, and executive functions (such as planning or impulse control). Some of these regions are the prefrontal cortex, the anterior cingulate cortex, and the striatum. These differences in the brain could be at the root of both the commonalities and differences between the two disorders.
- Disbalances in Neurotransmitters: Chemicals like dopamine and serotonin are key to regulating attention, mood, and behavior. In both disorders, these chemicals do not work as they should. For example, imbalances in serotonin may be related to impulsivity or repetitive behaviors seen in ADHD and autism.
- How the Brain Develops in Childhood: The brain forms rapidly during the first years of life, and any disruption in this process can cause problems. In the case of ADHD and autism, these disruptions may affect the brain connections necessary for social communication, attention, and impulse control, resulting in typical symptoms between the two.
ABA Centers of New Jersey and Autism Support
Understanding autism and ADHD is not just a matter of identifying symptoms; it’s about recognizing how each person experiences these conditions uniquely. If you have a child or know someone with autism, ADHD, or both, remember that there are resources, support, and therapies that can make a difference.
Do you have questions or need guidance? At ABA Centers of New Jersey, we are here to help you navigate the neurodiverse journey with empathy and practical solutions like ABA therapy. Call us at (855) 640-7888 or connect with us online, and let’s build a more inclusive future together!
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