ADHD and autism have several overlapping symptoms, and there's strong evidence the two conditions may be connected. Understanding the science behind that connection can help you create a medical or educational plan to support a loved one or yourself.
Understanding the Connection
Many people diagnosed with autism also struggle with attention deficit hyperactivity disorder (ADHD), a condition characterized by marked difficulty in attending and controlling impulses. In fact, according to a 2015 review of current research published in the journal Frontiers in Human Neuroscience, studies show that between 37 and 85 percent of children with autism spectrum disorder (ASD) are also diagnosed with ADHD at some point in their development. Additionally, a 2014 study in the journal Translational Psychiatry examined more than 17,000 adult twins to establish that 28 to 44 percent of adults with autism also meet the diagnostic criteria for ADHD.
How Are Autism and ADHD Similar?
While the two disorders are not the same, there are some similarities. According to a 2012 study published in Research in Autism Spectrum Disorders, the majority of children with ADHD did not display key characteristics of autism, which can include communication challenges, repetitive behaviors, and problems with social interaction. However, many children diagnosed with autism also displayed some of the core characteristics of ADHD, including the following:
- Inattention - A fundamental requirement for ADHD diagnosis is an impaired ability to pay attention in many situations. Frequently, people with autism also struggle with paying attention, although this is sometimes related to sensory overstimulaton.
- Hyperactivity - Again, this symptom of some types of ADHD also shows up in some people with autism. The need to move and fidget constantly appears in both populations, although it is not a requirement for diagnosis of either disorder.
- Impulsivity - Another major aspect of ADHD involves acting impulsively, or before fully considering the situation at hand. People with autism may also act on impulse.
In addition, there's significant overlap in one specific area of impulse control, called executive functioning, according to a 2009 study published in Psychiatry Research. Both children with ADHD and children with autism show significant impairments in their ability to plan and organize.
More Boys Than Girls
Males are much more likely than females to receive an ADHD diagnosis, and this same gender difference is present in ASD.
- The CDC reports that ADHD is much more prevalent in boys than in girls, with 13.5 percent of boys aged 3-17 carrying the label. Only 5.4 percent of girls in this age group have been diagnosed. This translates to boys being 2.5 times more likely to have ADHD.
- The CDC's ASD Data and Statistics report indicates the gender difference is even more pronounced in autism. In fact, boys are almost five times more likely to receive an autism diagnosis than same-aged girls.
Comparing Age at Diagnosis
The CDC's data for both disorders indicates autism is typically diagnosed a little earlier than ADHD, although this can depend on the severity of the disorder. The average age of diagnosis for ADHD is seven years, and the average age of diagnosis for high functioning autism is six years and two months. However, children with lower functioning levels show an average age of four years at diagnosis. In general, parents and caregivers tend to notice missed milestones with autism, but this is not always the case with ADHD.
Additionally, an earlier diagnosis of ADHD can mean a delayed autism diagnosis for children with both conditions. A 2015 study published in Pediatrics showed an initial diagnosis of ADHD could delay an autism diagnosis by an average of three years. This was not affected by the severity of the autism symptoms.
What the Connection Means to Families
With studies indicating there is significant overlap between ADHD and autism, parents and caregivers may wonder if their loved one has both disorders. As with anything related to parenting or caregiving, following your instincts is important.
Don't Stop at One Diagnosis
As the person who knows this individual the best, you may be the first to suspect that something else is going on. Since the 2015 Pediatrics study found an ADHD diagnosis could result in a missed or very delayed autism diagnosis, it's important to pursue your concerns with your pediatrician or other doctor if you feel your child may be struggling with more than one disorder. In the case of autism, early intervention can make a significant, lifelong difference in functioning level according to the University of Washington.
Know How ADHD and Autism Affect Learning
Every child learns in his or her own way, but both ADHD and autism can have a significant effect on school performance. If your child has both disorders, think about what helps him focus and learn. Does he do better in a classroom with a set routine and minimal distractions? Does he need to sit near the teacher's desk to help him stay focused? Communicate what you know about your child's learning to the teachers and therapists working with him and ensure these adaptations are documented in his individualized education plan (IEP).
Understand the Social Implications
Autism and ADHD both affect social functioning, but they do it in different ways. In the case of autism, challenges include attention, social communication, turn taking, non-verbal communication, and many other types of interaction. In ADHD, social challenges sometimes result from impulsive behavior or inattention to social cues.
When kids are affected by both disorders, it's important to offer as much support as possible at home and at school. Work with behavior therapists, school social workers, and other professionals to help give the child skills to overcome her challenges and navigate the world of peer interactions.
Research Medication Options
There are a number of pharmaceuticals designed to help mitigate some of the symptoms of ADHD, but medication isn't the ideal solution for everyone. Talk to your doctor about this option so you can understand the risks, as well as the potential benefits. It is difficult to determine how the two disorders affect one another and respond to medication, even on a case-by-case basis.
Autism and ADHD have many similarities when it comes to symptoms and to the populations they affect. If you are concerned that you or a loved one has ADHD and Asperger's Syndrome or another autism spectrum disorder, educating yourself about the connection can help you make sure you're getting the best help you can.