Social delays. Communication difficulties. Repetitive behaviours. What's behind them: ADHD? Autism? Both? When conditions overlap, parents need an intimate understanding of each diagnosis to manage treatment - and everyday life.

What Is Autism?

Autism is a complex neurobiological developmental disability that results in persistent deficits in social communication or interactions, plus restricted, repetitive patterns of behaviour; sensory issues may also be present. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), a diagnosis of autism spectrum disorder (ASD) is now appropriate for patients who, prior to 2013, may have been diagnosed with autistic disorder, Asperger's syndrome, childhood disintegrative disorder, or pervasive develop-mental disorder not otherwise specified (PDD-NOS) - all conditions characterised by social and communication impairments.

To merit an ASD diagnosis, a patient must experience significant impairment due to persistent deficits in the following areas, beginning at a young age:

• Social-emotional reciprocity - a failure to initiate or respond to social interactions, including back-and-forth conversations
• Nonverbal communicative behaviours used for social interaction - poor use of eye contact, body language, gestures, and facial expressions
• Developing, maintaining, and understanding relationships - difficulties adjusting behaviour for disparate social contexts, making friends, or showing an interest in peers

In addition to the above, a patient must display two of the following behaviours to qualify for an ASD diagnosis, assuming the behaviours are not better explained by another diagnosis:

• Stereotyped or repetitive motor movements, use of objects, or speech
• Insistence on sameness, inflexible adherence to routines, or ritualised patterns of verbal or nonverbal behaviour
• Highly restricted, fixated interests that are abnormal in intensity or focus
• Hyper- or hypo-reactivity to sensory input or unusual interest in sensory aspects of the environment

According to the Centres for Disease Control (CDC), "Individuals who have marked deficits in social communication, but whose symptoms do not otherwise meet criteria for autism spectrum disorder, should be evaluated for social (pragmatic) communication disorder.

ADHD vs. Autism

Attention deficit hyperactivity disorder (ADHD or ADD) and autism are neurodevelopmental disorders that impact similar brain functions. They are different conditions that share some similar behaviours - difficulty managing emotions, social awkwardness, the ability to focus only on things that interest them, and impulsivity. Scientists believe they share a common genetic link, which could explain why their comorbidity is common.

Differentiating autism from ADHD confuses many families. When a child can't sit still for homework or a meal, gets up during class, fidgets, or talks too much and too insistently, parents, caregivers, educators, tutors, and coaches think, "This kid must have ADHD!"

The first explanation most doctors arrive at is also ADHD. The condition is familiar, it's been around a long time, and there are effective strategies to manage it. It is important to remember, however, that almost any psychological or developmental disorder of childhood can look like ADHD, with or without hyperactivity. Kids under stress, living with learning disabilities, anxiety, depression, trauma, or sensory integration problems, can all exhibit symptoms that resemble ADHD. It takes a skilful evaluation to tease out explanations for the behaviours.

Diagnosing autism is frequently completed by a developmental paediatrician, child psychiatrist, child psychologist, or paediatric neurologist. Most insurance companies, and virtually all public schools, require a written assessment by a specialist before they provide, or pay for, services autistic children need.

No laboratory test exists to diagnose ASD; screening and diagnosis involve interviews, observation, and evaluations. Even when a professional imparts an opinion, they often hedge by saying, "Well, there are some typical behaviours, somewhat consistent with a diagnosis of a pervasive developmental disorder." This kind of talk is frustrating to the parents but is sometimes unavoidable. A follow-up assessment a year later might provide a definitive diagnosis.

Another reason for the confusion is that treatments for ADHD sometimes change the way autism presents in an individual. Frequently, a child diagnosed with ASD does not receive an additional diagnosis of ADHD. But, children on the autism spectrum can benefit from interventions that help children with ADHD, even if they don't have it.

Intervention Options and Distinctions

Some parents may prefer to start with non-medicinal therapies to manage behaviours associated with autism that hinder academic and interpersonal success. One mainstay ASD intervention is behavioural therapy administered by a psychologist who specialises in ASD or a professional trained in Applied Behavioral Analysis. Behavioral therapy reinforces an individual's strengths and discourages inhibiting behaviours. Posting lists, rules, and schedules to keep ASD kids organised can be helpful. Checking off items on a checklist can give autistic kids a sense of accomplishment when they complete tasks.

Physical exercise is a useful intervention for children with ADHD and/or autism, all of whom seem to have boundless energy. Channeling excess energy into physical activity, such as swimming or karate - which don't require a lot of interaction with other kids - allows them to burn it off without the pressures of socialising.

Medication can also form part of an individual's care plan. Because children with ASD have more unpredictable reactions to stimulants (the most common class of ADHD medication) compared to children with ADHD, they are less likely to be prescribed. Most paediatricians, and virtually all child psychiatrists, feel competent in prescribing stimulants for ADHD, but might refer a child with ASD to a psychiatrist or a psycho-pharmacologist before trying different types of medications or increasing the dosage of current ones.

A class of medicines called atypical neuroleptics is often effective at treating motor restlessness, repetitive behaviours, and sleep disturbance in children with autism. These include:

• aripiprazole (Abilify)
• quetiapine fumarate (Seroquel)
• risperidone (Risperdal)

Risperdal is the only one approved by the FDA for treating behaviours associated with autism. If atypical neuroleptics decrease symptoms, stimulant medication might not be needed.

Every child with autism can benefit from the support of a developmental and behavioural paediatrician or a child psychiatrist, child psychologist, or Applied Behaviour Analysis specialist with training in ASD. Having a specialist who understands what it's like to live with an active autistic child (is there any other kind?) is a bonus for parents, as well.

Article by Eileen Costello, M.D.

Published 13th May 2022
Published by ADDitude