top of page

Overlap Between ASD & ADHD

Attention Deficit Hyperactivity Disorder (ADHD) is most commonly characterized by series of developmentally inappropriate inattentiveness, hyperactivity and/or impulsivity that continue to persist throughout the course of time and has proven to negatively impact several areas of life (Antshel, Zhang-James, & Faraone, 2013). These areas of life which may become affected include school, social relationships, workplace, and at home (Flamez & Sheperis, 2015). It is a disorder that is common among children and can often persist into adulthood, which can cause significant daily life challenges as about 90% of adults with ADHD are undiagnosed (Flamez & Sheperis, 2015).

Many people believe that ADHD can be caused by certain environmental factors such as watching too much TV, being exposed to fluorescent lights, taking antibiotics, lead exposure, chemical cleaners, nutrition such as vitamin intake and sugar (Ben Feingold), and childhood experiences that could have triggered the disorder. There is not much evidence supporting these claims, in fact the science found behind ADHD indicates that it is a genetic, neurodevelopmental disorder that is not caused by one thing.

Although the exact cause of ADHD is unknown, certain risk factors of ADHD involve both biological and environmental factors. Some environmental risk factors of ADHD can incude prenatal exposure to lead, PBC, mercury, alcohol and tobacco, polybrominated diphenyl ethers (PBDE), maternal obesity/high fat diets, and maternal stress (Antshel, Zhang-James, & Faraone, 2013). Some biological factors contributing to ADHD include hereditary, abnormal connectivity in the brain (miswiring), and regions of chromosomes impacting development (Antshel, Zhang-James, & Faraone, 2013).

According to Flamez and Sheperis (2015), it had been concluded that ADHD was not an obvious or easy disorder to be diagnosed. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM), it previously focused of diagnosing ADHD by primarily focusing on behavioral traits related to hyperkinesis. One of the first accounts of observing ADHD took place in 1845 when a German psychiatrist named Heinrich Hoffman described a young boy he referred to as “fidgety Phillip” as unable to sit still during dinner, rocking back and forth while sitting in his chair, resulting in him pulling the table cloth onto the floor along with the dinner. This later helped other psychiatrists discover more about the disorder. Since ADHD was primarily diagnosed as hyperkinesis, it was misidentified as a somatic/behavioral issue.

In 1902, a British physician named George Frederick Still published work in which he described symptoms of ADHD, but were classified as kinetic behavior, resulting in others continuing to do so for the remainder of the 20th century (Flamez & Sheperis, 2015). Many tried exploring the disorder through MRI tests, but the results were inconclusive, ruling out the possibility that it was a brain dysfunction (Flamez & Sheperis, 2015). Once the 1970’s came around, many started recognizing the reality of attention deficit, which led to the 1980’s publication of the DSM-III in which the inattentive and hyperactive types of the disorder were clearly differentiated (Flamez & Sheperis, 2015). In 1987, the DSM-III-R finally renamed it attention-deficit/hyperactivity disorder, which later editions of the DSM brought upon the acronym, ADHD (Flamez & Sheperis, 2015).

Treatment of ADHD can involve a variety of intervention strategies including medication (stimulants, noradrenergic reuptake inhibitors, and antihypertensive medications) and psychosocial intervention that focus on parent-child relationship. Treatment of ADHD often involves prescribing medication, such as amphetamines. Amphetamines are a common drug used to treat ADHD, however there is a lot of controversy around using the drug with children due to the intense side effects they can experience. Some side effects include mood changes, loss of appetite, and loss of sleep (Smith, 2012). The debate between whether or not prescribing these drugs is beneficial is ongoing. Some believe that it is a threat to the country, while others believe that the pharmaceutical companies only seek to control children while making billions off the profits (Smith, 2012).

Autism Spectrum Disorder (ASD)

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that impairs and restricts social communication and interaction among individuals. Additionally, individuals with ASD often demonstrate repetitive patterns in behavior, interests, and/or activities (Flamez & Sheperis, 2015). Since it is based off of behavioral observations, it is similar to other DSM-5 disorders such as ADHD which is based off observations of behavior. However, due to the complex nature of the disorder, decades of research still have not provided clear, exact answers as to how or why ASD develops and how it can be cured. It is estimated that about 2% of children has been diagnosed with ASD, and this rate continues to grow (Flamez & Sheperis, 2015). Additionally, ASD is 4-8 times more prevalent in males than females, which is thought to be attributed to heritability and the X chromosome (Flamez & Sheperis, 2015). The onset of ASD is very early in development, about 50% of parents whose children have been diagnosed with ASD expressed their concerns within the first year of their child’s life, and 90% of parents were able to identify associated difficulties by the time their children turn 2 (Flamez & Sheperis, 2015).

Currently, there is no known cause of ASD, however certain risk factors have been identified to be linked to the etiology of ASD including biological factors such as, genetics, miswiring of brain connections, and chromosomal abnormalities (Antshel, Zhang-James, & Faraone, 2013). Additionally, environmental factors have been found to contribute to ASD including prenatal exposure to lead, PCB, mercury, alcohol/tobacco, polybrominated diphenyl ethers (PBDE), maternal obesity/high fat diets and stress. Similar to ADHD, treatment for ASD typically is a process of elimination when it comes to finding the right combinations of intervention strategies. Some intervention strategies include medication (methylphenidate, psychosocial intervention, applied behavior analysis (ABA), discrete trial training, incidental teaching, pivotal response training, speech/language therapy (Flamez & Sheperis, 2015).

Historically, Leo Kanner was the first person to successfully explain autism in his detailed case notes of children he had observed and took notice of their shared characteristics, which later provided a starting point for diagnosing autism (Singh, 2015). Shortly after Kanner’s discovery, a pediatrician from Austria named Hans Asperger made a similar discovery by describing the first case of Asperger’s syndrome from children he had observed, but differing slightly from Kanner’s observations in language, motor, and learning abilities (Singh, 2015). Unfortunately, Asperger’s contribution was not recognized immediately and did not become recognized until his work reached countries where people spoke English (Singh, 2015). Similar to others, Kanner built his knowledge upon psychoanalytic thought, which identified autism as a kind of psychosis related to childhood schizophrenia which was thought to be attributed by mothers not being nurturing enough towards their children. This was later debated by Dr. Bernard Rimland in 1960 who was the first to argue the psychogenic theory of autism by offering the idea that it was a medical condition based on genetics, thus refuting the idea that autism was caused by cold, overly-anxious mothers and successfully shifted the blame away from parents (Singh, 2015).

Infantile autism was not included in the DSM until 1980 and the diagnostic criteria has since undergone many significant modifications over the past 30 years. Initially, the DSM separated the categories social interaction and social communication, however they have since grouped them into one category (Flamez & Sheperis, 2015). Today, it is clear that early intervention is critical for ensuring the positive developmental trajectory of an individual with ASD (Flamez & Sheperis, 2015).

Comorbidity of ASD and ADHD

ASD and ADHD have a lot of overlap and therefore can make it difficult to treat both disorders effectively. For example, Factor et al. (2017) explored the possibility that the presence of anxiety and Attention Deficit Hyperactivity Disorder (ADHD) symptoms further impair the social functioning in children with Autism Spectrum Disorder (ASD). It was discovered that the symptoms of anxiety and ADHD can in fact worsen the social functioning of an individual with ASD. Anxiety has been discovered to be the most commonly reported issue among children with ASD as it entails a high prevalence of social fear, worry, and obsessive tendencies or behaviors. Social anxiety has been strongly correlated to impairments in social functioning, leading to decreased motivation to socialize. Furthermore, this could provide insight into the relationship between anxiety and repetitive/restrictive behaviors such as insisting sameness (repetitive and restrictive behaviors). Some examples of repetitive and restrictive behaviors may include motor movements such as hand-flapping, rocking back-and-forth, the repetitive use of objects such as toys or repeatedly turning a light switch on and off. More severe symptoms include adhering to a strict routine or insisting that items must remain in the same place they put them in, such as lining up cars and insisting that they are not moved from their position (Herscu et al., 2020).

Repetitive and restrictive behaviors have been discovered to further lead to adverse social implications such as peer rejection, bullying, depressive symptoms, fewer friends, and thoughts of self-harm. Additionally, they found that there were distinct differences between children with ASD but without anxiety compared to their counterparts, with children with both ASD and anxiety experiencing less desirable social outcomes.

Pharmacological treatment research has seen a decline in recent years due to ADHD medication taking the forefront in treatment for ADHD symptoms, which often overlap with ASD symptoms. Stimulants are a commonly used medication used to treat ADHD and ASD symptoms, however the efficacy of the drug has been questioned due to the adverse side effects individuals experience, including irritability, self-injury, and stereotypy (Davis & Kollins, 2012).


In conclusion, ASD and ADHD are comorbid disorders that require a highly specified and intentional treatment plan, one in which produces the most desirable outcome for the individual living with both conditions. Each case is different and requires effective and continued assessment of all areas of the individual’s life in order to effectively treat both coexisting conditions.



Antshel, K. M., Zhang-James, Y., and Faraone, S. V. (2013). The comorbidity of ADHD and autism spectrum disorder. Expert Review of Neurotherapeutics, 13(10), 1117-28.


Center for Disease Control (2020). Autism and Vaccines. Retrieved Feb 20, 2021, from

Davis, N. O., & Kollins, S. H. (2012). Treatment for co-occurring attention Deficit/Hyperactivity disorder and autism spectrum disorder. Neurotherapeutics, 9(3), 518-30. doi:

Factor, R., Ryan, S., Farley, J., Ollendick, T., & Scarpa, A. (2017). Does the Presence of Anxiety and ADHD Symptoms Add to Social Impairment in Children with Autism Spectrum Disorder? Journal of Autism & Developmental Disorders, 47(4), 1122–1134.

Flamez, B., and Sheperis, C. J. (2015). Diagnosing and treating children and adolescents: A guide for mental health professionals. ProQuest Ebook Central

Herscu, P., Handen, B. L., Arnold, L. E., Snape, M. F., Bregman, J. D., Ginsberg, L., Hendren, R., Kolevzon, A., Melmed, R., Mintz, M., Minshew, N., Sikich, L., Attalla, A., King, B., Owley, T., Childress, A., Chugani, H., Frazier, J., Cartwright, C., & Murphy, T. (2020).

The SOFIA Study: Negative Multi-center Study of Low Dose Fluoxetine on Repetitive

Behaviors in Children and Adolescents with Autistic Disorder. Journal of Autism &

Developmental Disorders, 50(9), 3233–3244.

Missouri Autism Guidelines Initiative. (2012). Autism Spectrum Disorders: Guide to Evidence-Based Interventions.

Shaw, M., Hodgkins, P., Caci, H., Young, S., Kahle, J., Woods, A. G., & Arnold, L. E. (2012). A systematic review and analysis of long-term outcomes in attention deficit hyperactivity disorder: Effects of treatment and non-treatment. BMC Medicine, 10, 99.


Singh, J. S. (2015). Multiple autisms: Spectrums of advocacy and genomic science. ProQuest Ebook Central

Smith, M. (2012). Hyperactive : The controversial history of adhd. ProQuest Ebook Central

TED (Producer). (2012). TedTalks: Ami Klin—A new way to diagnose autism [Video file].

15 views0 comments

Recent Posts

See All


bottom of page