Why Does ADHD and Autism Seem to Run in Families?

One of the most common questions I get from parents is, “Why do so many people in my family seem to have ADHD or Autism?” Or even more pointedly, “Is it my fault my kid has it too?” That second one usually comes with a heavy sigh, a mix of guilt and confusion, and often a quiet, reluctant realization: “I think I might have ADHD (or Autism) too.”

Here’s the truth — no, it’s not your fault. But yes, both ADHD and Autism often run in families. And there’s a very real, very scientific reason for that.

The Genetics of ADHD and Autism

ADHD is one of the most heritable mental health conditions we know of. When researchers talk about heritability, they’re referring to how much of a condition can be explained by genetic factors — and for ADHD, that number sits between 70% and 80%.

Autism also has a strong genetic component, with heritability estimates ranging from 60% to over 80%, depending on the research and specific diagnostic criteria used.

Let’s break that down. Whether it’s ADHD or Autism, these aren’t caused by one single gene — there’s no “ADHD gene” or “Autism gene.” Instead, they’re shaped by a collection of gene variants that, when present in certain combinations, increase the chances of someone being neurodivergent.

Most people — even neurotypical people — carry some of these genetic variants. But the more someone has, the more likely they are to develop traits associated with ADHD or Autism. In people who are diagnosed, there are often dozens or even hundreds of these small genetic differences at play, influencing how their brains process information, regulate behavior, or respond to the world.

It’s All in the Mix

During conception, a child’s DNA is built from a mix of genetic material from both parents. So if one or both parents are neurodivergent, there’s a higher chance their child will inherit more of those variants. That’s why we often see multiple people in the same family with ADHD, Autism, or a blend of both — sometimes diagnosed, sometimes not.

This isn’t just about genes, though. Families also share environments — routines, communication styles, emotional responses, and stressors. A child growing up in a household where a parent has undiagnosed or unsupported ADHD or Autism may also be navigating the ripple effects: emotional dysregulation, sensory overwhelm, inconsistent routines, or strained communication. Those patterns can reinforce or complicate the child’s own neurodivergent experience.

It’s Not Always Just ADHD or Autism

Before anyone gets a diagnosis, especially as an adult, it’s important to rule out other possible causes for executive function struggles, emotional intensity, or social differences. That’s why professionals may recommend assessments that screen for environmental and medical factors that can mimic or overlap with neurodivergence.

These might include:

• High lead levels

• Thyroid disorders

• Borderline Personality Disorder

• Other medical or neurological conditions

Ruling out these factors is a key part of getting the right diagnosis and the right kind of support. And for a lot of people, Autism and ADHD aren’t either-or — many individuals are diagnosed with both, which can affect how traits show up and how support should be structured.

This Isn’t About Blame

If you’re reading this and realizing that you or your child might fall somewhere on the ADHD or Autism spectrum, it can feel overwhelming — even a little scary. But this isn’t about guilt or blame. It’s about understanding.

• Understanding that your child isn’t broken.

• Understanding that you’re not broken either.

• Understanding that ADHD and Autism are neurodevelopmental differences — not character flaws or parenting failures.

And most importantly, understanding that you can do something with this knowledge.

What Do You Do With This Information?

If ADHD or Autism runs in your family, here’s where that knowledge becomes power:

• Look inward. If you’ve always felt like you processed things differently, or that life’s always been just a bit harder than it should be, consider getting assessed. Many parents don’t realize they’re neurodivergent until they start advocating for their kids. That insight can help you break cycles and build a more supportive family structure.

• Get proactive about parent training. Whether your child has ADHD, Autism, or both, learning how their brain works gives you tools. You’ll start to understand executive function challenges, sensory sensitivities, and communication needs in ways that lead to connection, not conflict. This has the added benefit of teaching you about your own neurodivergence and this can radically change how you support your child — and yourself. Check out ScienceWorks Behavioral Health, our partner that does adult assessments and therapy to find out more about these benefits!

• Work with a psychiatrist or your personal physician. Work with professionals to find out if medication can help you with the symptoms that you struggle with. Also, find a good therapist that understands ADHD and trauma and work with them, adults diagnosed with ADHD often deal with untreated trauma, which can make ADHD symptoms significantly worse. 

• Build systems that work for your family. Visual schedules, timers, routines, and externalized supports aren’t crutches — they’re tools. And they’re not just for kids. These systems help the whole family manage stress, stay on track, and reduce burnout.

• Model emotional repair. Meltdowns, shutdowns, and emotional dysregulation happen. What matters is how you reconnect afterward. Showing your child that it’s okay to have big feelings — and okay to make things right — teaches resilience and emotional safety.

Nature, Nurture, and Neurodivergence

Yes, ADHD and Autism are highly genetic. But genes are just the blueprint — not the final product.

Having neurodivergence in the family doesn’t mean chaos. It means difference. It means sensitivity, creativity, persistence, and unique perspectives. It means you need a game plan that fits your family — not a one-size-fits-all parenting script written for neurotypical brains.

You’ll parent differently. You’ll communicate more intentionally. You’ll drop the unrealistic expectations and start focusing on what actually works for your kid, and for you.

And the more you understand, the more you’ll see that this isn’t a burden — it’s a map. One that helps you show up for your child and yourself with more clarity, compassion, and confidence.

This is exactly why we partner with ScienceWorks Behavioral Healthcare, PLLC — to provide assessments and therapeutic support for adults with ADHD, Autism, OCD, and Trauma. They understand how these conditions overlap, how they affect daily life, and how to help people get the clarity they need. Their evaluations are affordable, and they walk you through how to get reimbursed through insurance.

If you’ve been wondering where to start, this is it.

Check them out and take that next step toward understanding and support!