Co-Occurring Conditions of Autism and ADHD

My daughter Ainsley was constantly sent to the principal’s office as a child. She was wild and unruly, couldn’t sit still, and jumped on desks. She was overly chatty and careless. She talked back to teachers who didn’t understand her and was often called a “bad child.”

Estimates are that 30 to 50 percent of autistic children have co-occurring ADHD.

What is ADHD?

The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) defines ADHD as “a neurodevelopmental disorder defined by impairing levels of inattention, disorganization, and/or hyperactivity-impulsivity.” Symptoms must meaningfully interfere in a child’s day-to-day functioning and persist for at least 6 months before age 12 in at least two settings (i.e., home, school, social settings).

Dr. Geraldine Dawson, the William Cleland Distinguished Professor of Psychiatry and Behavioral Sciences at Duke University and Founding Director of the Duke Center for Autism and Brain Development explains that children with ADHD often have challenges in self-regulation and executive functioning that hinder their ability to plan, organize, problem-solve, focus, pay attention, remember instructions, multitask, and manage emotions.

Children with ADHD often know what they should do, but struggle with execution. “ADHD Paralysis” occurs when they become overwhelmed or overstimulated and move into avoidance or shut-down mode.

Unfortunately, misunderstandings about ADHD can lead parents, teachers and others to label a child as lazy, unmotivated, disruptive or defiant. The constant admonishments and punishments only serve to lower their self-esteem.

It used to be thought that boys were twice as likely to have ADHD than girls. Boys exhibit more outward behaviours, but the gap is narrowing with greater awareness and sensitivity as to how ADHD presents in girls.

ADHD is not a behaviour disorder. It is not a mental illness. It is not due to lax parenting or too much screen and video time.  It has a strong genetic component, with co-occurrence in families. Environmental factors like stress and trauma also play roles, although the exact cause(s) of ADHD are not known.

How is ADHD diagnosed and treated?

As with autism, there are no medical, lab, or blood tests that identify ADHD. Diagnosticians ask about the child’s developmental and medical histories, family history, mental health, and school performance. Parents, caregivers, and teachers also play a crucial role in filling out questionnaires and providing behavioural observations in different settings. Finally, the diagnostician observes the child directly to see if their behaviour meets the diagnostic criteria for ADHD.

ADHD is most often treated through a combination of medications and behaviour therapy. Dr. Dawson comments, however, that children often respond well to behavioural interventions without medications. Thus, starting with behavioural interventions and adding medications later as needed is important. Children who have a combined approach of behavioural interventions and medication have been found to have better outcomes than those who only take medications. As I’ve seen with my kids, medication and therapy can be powerful partners.

Common medications include methylphenidates (e.g., Ritalin, Concerta), amphetamines (e.g., Adderall, Dexedrine, Vyvanse), non-stimulants (atomoxetine/Strattera), and guanfacine (Intuniv, Tenex). Due to potential side effects such as irritability and emotional dysregulation, Dr. Dawson cautions us to “start low, go slow.”

In behaviour therapy, children learn to identify and change their thought patterns and develop coping techniques. They also learn to regulate their emotions, enhance their problem-solving abilities, and develop skills to help with executive functioning.

What about co-occurring autism and ADHD?

The overlap between autistic and ADHD behaviours can complicate diagnoses. Many autistic children demonstrate those core ADHD behaviours of distractibility, inattention and impulsivity, as well as language delays, heightened sensory sensitivities, a lack of focus/hyper-focus, problems with self-regulation and emotions, and difficulty with planning and organization.

The difference comes down to the reasons for the behaviour. If a child isn’t paying attention, is it because they don’t understand the instructions (autism) or because they cannot sit still long enough to focus on what’s being said (ADHD)? Is it because they don’t comprehend social cues (autism) or because they’re too distracted to engage (ADHD)? Do they have difficulty understanding social expectations, for example, sitting in their seat? Can they complete a task once they understand the instructions?

Dr. Dawson explains that autistic children with ADHD usually obtain their ADHD diagnosis first, mainly because disruptive ADHD behaviours tend to overshadow autistic behaviours. Their autism diagnosis often occurs after 6 years of age, which means they miss out on early autism intervention. Trust your gut as a parent if you observe “autism signs”, such as lack of eye contact, not pointing or gesturing, repetitive and restrictive behaviours or restricted interests, and your doctor is only paying attention to the ADHD behaviours.

Duke University is involved in exciting research identifying patterns of healthcare utilization in babies as potential screening tools for autism and ADHD. Autistic children less than one year of age are more likely to see neurologists, gastroenterologists, physical therapists and optometrists, while those with ADHD visit the emergency room more, possibly due to risk-taking behaviours and accidents.

Significant progress can be made with supports and modifications, such as simplifying and chunking language to ensure your child understands instructions and expectations or using visual supports like gestures, pictures, or social stories. A team at Duke has found that greater progress can be made by ensuring that early autism intervention addresses a child’s ADHD-related issues so they can learn to engage and socially interact.

The book What Science Tells Us about Autism Spectrum Disorder: Making the Right Choices for Your Child, which Dr. Dawson co-authored, points to the importance of exercise, sleep and nutrition as foundational building blocks for children with both autism and ADHD. These are critical for brain development, emotional regulation, mood and attention.  She adds that while there is no substantial evidence supporting special diets, parents who decide to implement a dietary change should always check with their child’s family doctor to ensure they maintain good nutrition, keep detailed data and change only one food at a time.

She also believes that parents must be at the centre of their child’s behavioural interventions, with guidance from a qualified therapist.  As she says, “Every interaction is an opportunity for learning.” She finds parents adept at learning strategies to promote their child’s skills in their natural environment, whether at the park, dinner, bath or bedtime.  Parenting books, such as An Early Start for Your Child with Autism, equip caregivers with strategies to use during everyday activities that promote learning, communication and social interaction.

Focus on structure and routine, anticipate potential emotional and behavioural triggers and give your child lots of positive attention, praise and motivational rewards.  Build on their strengths and make them feel good about themselves.

Dr. Dawson is delighted that more and more people are recognizing that differences are not necessarily deficits.  Yes, there are many challenges, but there are also wondrous gifts in looking at the world in a unique manner and finding novel solutions to longstanding problems that benefit us all.

Embrace these!