Autism rarely shows up entirely on its own. Understanding the conditions that commonly co-occur with autism can help you get a fuller, more accurate picture of your child's needs — and make sure nothing important gets missed.
ADHD
Attention-deficit/hyperactivity disorder (ADHD) co-occurs with autism at a notably higher rate than in the general population. Historically, autism and ADHD couldn't even be diagnosed together under older diagnostic rules, but that changed with the DSM-5, reflecting growing recognition that many children genuinely have both. Symptoms can overlap in confusing ways — difficulty with attention, impulsivity, and executive functioning show up in both conditions — which is part of why a thorough evaluation matters rather than assuming one diagnosis explains everything.
Anxiety
Anxiety disorders are common among autistic children and adults, and can stem from multiple sources: the genuine difficulty of navigating a social and sensory world not built with autistic processing in mind, the exhaustion of masking (discussed in Autism in Girls), and difficulty with unpredictability or change, which many autistic individuals find genuinely distressing. Recognizing anxiety as a distinct, treatable co-occurring condition — rather than just "part of the autism" to be tolerated — matters for getting your child appropriate support.
Epilepsy and Seizure Disorders
Epilepsy occurs at meaningfully higher rates in autistic individuals than in the general population, with some research suggesting the association is strongest in autistic individuals who also have intellectual disability. If your child has any symptoms suggestive of seizures (brief staring spells, unusual repetitive movements, episodes of unresponsiveness), it's worth raising this specifically with your child's pediatrician or neurologist rather than assuming it's autism-related behavior alone.
Gastrointestinal Issues
Many autistic children experience gastrointestinal difficulties — including constipation, feeding difficulties, and general GI discomfort — at higher rates than the general population. GI discomfort can also contribute to behavioral changes that might otherwise be misread as purely behavioral, which is part of why ruling out underlying medical causes is an important part of a comprehensive approach to behavior support.
Sleep Difficulties
Sleep problems, including difficulty falling asleep, staying asleep, and irregular sleep patterns, are common among autistic children and can significantly affect daytime behavior, mood, and learning. Addressing sleep is often an underrated but high-impact piece of overall support.
Intellectual Disability
Autism and intellectual disability can co-occur, though many autistic individuals do not have intellectual disability — the two are distinct diagnoses that happen to overlap in some individuals but not others. A comprehensive evaluation should assess both separately rather than assuming one based on the other.
Why the Full Picture Matters
Understanding the complete picture of what's going on for your specific child — not just the autism diagnosis in isolation — helps ensure that a co-occurring anxiety disorder gets treated as anxiety, a sleep problem gets addressed as a sleep problem, and behavioral concerns aren't automatically assumed to be "just autism" when something else might be contributing. A good BCBA should be asking about this broader picture as part of a comprehensive assessment, and coordinating with your child's medical team as needed.
For Mount Pleasant-Area Families
If your Mount Pleasant-area child has autism alongside other diagnoses, our BCBA, Kimberly Blazer, takes the full picture into account when building a treatment plan — not just the autism diagnosis in isolation. Our BCBA Assessments & Treatment Planning service is designed around exactly this kind of goal. our in-home ABA therapy in Mount Pleasant page has more information, or Get Started Today to get started.
This article is part of our complete guide, What Is Autism Spectrum Disorder? Clinically reviewed by Kimberly Blazer, BCBA.