If your child has an autism diagnosis, chances are they’re also navigating additional challenges as well. That’s because autism is a condition that rarely exists in isolation. Research shows that 70–90% of children with ASD have at least one co-occurring condition that affects their daily life, learning, and behavior.
This guide will help you understand what co-occurring conditions (or comorbidities) are, which ones are most common, and why recognizing them matters for your child’s care.
Co-occurring conditions, or comorbidities, are separate diagnoses or challenges that show up alongside autism, like having ADHD or a sleep disorder in addition to an ASD diagnosis. They’re not caused by autism, but they do share overlapping neurological pathways, which is why they commonly appear simultaneously.
It’s helpful to know the difference between a core autism behavior and a behavior that points to a separate condition. Some behaviors are known features of autism, but other behaviors might be signals for something else entirely. Spotting this difference is important, because what looks like “just an autism behavior” could actually be a separate, treatable issue that needs its own specific support plan.
Autism affects the way the brain processes information and connects to the body. Many conditions that overlap share the same neurological foundations, it’s not an accident that the percentage of autism comorbidities is so high.
These comorbid conditions can also be intensified because of sensory processing differences, or they can be harder to notice and treat due to communication barriers—two issues that typically come with an ASD diagnosis.
The following are some psychiatric and behavioral conditions which frequently accompany autism:
30–60% of children with autism also meet ADHD criteria. The two conditions actually look similar at surface level—they both affect attention, executive functioning and impulse control. They need different support strategies, however, and a child with a diagnosis of both ADHD and autism would benefit from a treatment plan that takes both disorders into consideration.
40–84% of children with autism have anxiety, making it one of the most common comorbid conditions in autism. But anxiety often looks different in children with ASD—it can show up as severe rigidity, avoidance, or meltdowns instead of ’typical’ anxiety symptoms like worry, overthinking, or restlessness. It can also present as social or generalized anxiety, or as specific phobias.
10–20% of children with autism have depression or other mood disorders, and this number is higher in adolescents and adults with autism.
Depression is often underdiagnosed in people with autism. This is because the communication differences common in autism can mask symptoms of depression, such as a low mood or lack of energy. It can also be missed because children with autism often struggle to express their feelings.
10–17% of children with autism have OCD and show repetitive behaviors. This presents a unique diagnostic challenge, as repetitive behaviors can present themselves in both conditions. The key is distinguishing between an OCD compulsion and an autism-related repetitive behavior, which is often self-regulating and helpful for a child.
This distinction is important when it comes to treatment, because treating autism-related repetitive behaviors with methods used to treat OCD would be counter-productive.
The following are some physical and developmental conditions which frequently accompany autism:
50–80% of children with autism have a sleep disorder, making it a widespread co-occurring challenge. It can present as difficulty falling asleep, waking up in the night, or extremely early rising. This affects the whole family as well as the child, and can affect a child’s emotional regulation and ability to benefit from therapy.
Epilepsy and seizure disorders are much more common in children with autism, affecting 25–40% of children with ASD compared to only 2–3% of the general population. The risk of seizures is higher when a child has intellectual disabilities alongside autism, and they can begin to emerge in either early childhood or during adolescence.
GI problems are often not identified because children with autism aren’t always able to verbally communicate their discomfort, but they are significantly more common in children with autism.
If a child’s behavior seems to escalate and worsen for no clear reason, it’s worth investigating if they have any gastrointestinal issues (such as constipation, abdominal pain, or diarrhea).
Many children with autism keep a limited diet because they have strong sensitivities to the textures, tastes, smells, and even colors of food. This goes beyond the regular picky eating that’s common in children and can overlap with Avoidant/Restrictive Food Disorder (ARFID).
When this happens, there are two strong concerns: the possible impact on nutrition from the restricted diet, and the mealtime behavior challenges caused by a child’s strong sensitivities.
Sensory processing differences are not a separate diagnosis in the DSM-5, but for many children with autism, they are a core feature of their disorder that affects their entire life.
This can show up as hyper- or hypo-sensitivity to things like sound, light, texture, and movement. Since sensory processing differences shape how a child experiences the world, they interact with and affect nearly every other comorbid condition listed here.
It’s very easy to mistake symptoms of autism comorbidities for other issues.
If a child is dealing with untreated GI pain, their aggravation can be seen as a behavior problem. In the case of sleep deprivation, the symptoms—reduced attention and regulation—can be what gets noticed instead of the underlying issue. Anxiety can just look like an attitude problem or lack of interest.
But it’s important to identify and properly diagnose any conditions associated with autism. When these issues are addressed, ABA therapy can become much more effective, and daily life improves greatly for everyone involved.
If an ABA assessment only takes autism behaviors into account, it will lack important context and skip necessary steps in treatment. Co-occurring conditions should have an impact on the way treatment plans are arranged and structured.
For example, a child with ADHD could need shorter sessions or more reinforcement than usual. A child with untreated anxiety may struggle to engage in new activities and require extra assistance and reassurance. A child with gastrointestinal issues needs their pain addressed before they can handle behavioral support.
The amount of time ABA therapy takes to work is often affected by whether these other factors have been identified and addressed, within ABA therapy or separately. An effective ABA assessment looks at the whole picture.
It’s essential to ensure your child’s care team looks beyond just the autism diagnosis. The most effective support plan requires a true team effort: your child’s medical providers, BCBAs, and other specialists should all collaborate and work together. When everyone shares information and creates a unified strategy, the plan will fit the full picture of your child’s unique needs.
The most common autism comorbidities include anxiety, ADHD, sleep difficulties, GI issues, epilepsy, and sensory processing differences.
It’s not a coincidence. The high number of comorbid conditions in autism happens because of the way autism affects brain development and how a child processes sensory information. Autism shares common roots with many other medical and neurological conditions, which is why they often appear together.
Any sudden, noticeable or specific change in your child’s behavior, sleep, eating, mood, or physical health is worth discussing with their care team. It’s also worth carrying out a comprehensive evaluation to ensure no issues are being left unnoticed.
ABA therapy can support the behavioral changes that appear because of the co-occurring disorder. It should not be relied on to treat the co-occurring condition, however; it works best as part of a coordinated care plan that addresses all your child’s needs.
If it would be worthwhile for you to involve another specialist such as a neurologist, sleep specialist or mental health provider, you should. Your child’s BCBA can help you decide which additional support would be beneficial for your child.
Comorbid conditions will directly shape how an ABA therapy plan is structured. The details and circumstances of the condition decide what goals are prioritized, the length and structure of sessions, and what will be measured as progress.