Is ADHD Hereditary & Can It Be Developed?

Reviewed by Heather Cashell, LCSW

Published 07/17/2022

The contemporary concept and symptoms behind ADHD have been around for several hundred years. With that being said, it wasn’t until 1987 that the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) officially adopted the name attention-deficit hyperactivity disorder (ADHD).

Over time, the amount of people living with ADHD has risen significantly. Recent data suggests that over six million children have ever been diagnosed with ADHD, but that doesn’t even begin to include all the children and adults unaware of their symptoms. As diagnoses rise, so should the awareness.

Unfortunately, many people don’t receive the help they need to live a happy life. Not only that, but a wide amount of confusion remains in regards to what causes ADHD and where it comes from. While we continue to learn more about the inner workings of ADHD, there remain more questions than answers.

Some researchers believe ADHD is hereditary and caused by genetics, while others wonder if you can develop ADHD. In fact, this is one of the most burning questions surrounding this topic, and it’s one researcher is digging into every single day.

So, Is ADHD Hereditary, Or Is It Developed?

There was a time when researchers believed environmental factors and bad parenting caused ADHD. There was also a time when researchers were convinced ADHD was a result of poor nutrition, specifically the sugar content in the food we consume.

Today, researchers take a more conservative approach to understanding the causes of ADHD — not because they’re not interested in understanding it, but because they’ve uncovered a wide range of potential risk factors that all seem to play a role in ADHD.

Of all the potential risk factors researchers have identified, the one they pay the most attention to today is genetics. A variety of studies link heredity and genetics to ADHD, which means there’s a good chance it’s passed down to a child from one or both parents.

That also means siblings have a higher chance of being diagnosed with ADHD if another sibling is living with the disorder. In fact, an identical twin living with ADHD is more likely to see their twin diagnosed with the disorder as well.

Several years ago, researchers began exploring the possibility of ADHD being developed. While there was a wide range of people diagnosed later in life, it generally didn’t mean it was developed in their adult years. For the most part, it meant the symptoms were either masked in their younger years, or the symptoms were misdiagnosed as something else.

Although research is ongoing and there isn’t a final answer to the question, a majority of the research points to ADHD is genetic and hereditary, as opposed to being developed over time. Symptoms might get worse over time, but that doesn’t mean it was developed over time.

How Does ADHD Affect The Brain?

While diet, over-stimulating activities, or inconsistent parenting, and other environmental factors may play a role in ADHD, it’s clear that they don’t cause ADHD. There is often an underlying condition that’s causing the symptoms, and a majority of the research today suggests those issues are rooted in neurochemistry.

With brain imaging and other technological advances in medical science today, researchers can take a closer look at an individual’s brain. They can observe how they work, how they don’t work, and potentially understand the reasoning behind a person’s behavior.

When studying the brain of an individual with ADHD, there are several clear differences in brain structure and brain function compared to an individual without ADHD. Since the brain is responsible for everything we do, these differences start to explain why people with ADHD live with impulsivity, inattentiveness, and hyperactivity symptoms.

As far as brain structure is concerned, neuro-imaging and brain images suggest that a child’s brain matures much more slowly when living with ADHD than a child not living with ADHD. This is often why children have a harder time learning, developing, and growing when living with ADHD.

In addition to that, MRI imaging has shown that certain areas and regions of the brain are smaller in those living with ADHD. Researchers’ most common regions are the prefrontal cortex, cerebellum, basal ganglia, and striatum.

As far as brain function is concerned, researchers have revealed that neurotransmitter activity in the brain is different when living with ADHD. Although several neurotransmitters play a role, dopamine is the one that raises the most eyebrows when it comes to ADHD.

More specifically, researchers are interested in certain proteins and genes involved in the production, synthesis, release, and breakdown of dopamine. For those living with ADHD, dopamine levels are generally low, and it results in difficulty seeking or feeling pleasure — even when doing something you love or have a strong passion for.

There are four major brain areas that experience low levels of dopamine and neurotransmitter activity — the limbic system, the frontal cortex, the basal ganglia, and the reticular activating system (RAS). Let’s take a closer look at those four areas and what they’re responsible for:

  1. Basal Ganglia – a part of the brain highly responsible for motor control and movements, but also plays a role in executive functions, motor learning, emotions, and behavior. It helps other areas of the brain communicate with each other. When there are low levels of dopamine, it causes the brain to ‘short-circuit,’ resulting in difficulty paying attention.

  2. Frontal Cortex – a region in the brain highly responsible for high-level cognitive function, such as attention, memory, executive function, organization, problem-solving, spontaneity, and impulse control. Low levels of dopamine in this region lead to hyperactivity and impulsivity.

  3. Reticular Activating System (RAS) – a network of neurons in the brain that plays a major role in motivation, behavior arousal, consciousness, and alertness. It’s used as a filter to direct sensory stimuli to the cerebral cortex. A low level of dopamine in this area causes hyperactivity, impulsivity, and inattentiveness (the three major symptoms of ADHD).

  4. Limbic System – an area located deep in the brain responsible for regulating emotions and behaviors, especially behaviors needed for survival. It also plays a role in motivation, learning, and memory. Low levels of dopamine in the limbic system cause inattention, difficulty staying still, and insatiable emotions.

When someone is living with ADHD, healthcare professionals are extremely interested in looking at the individual’s brain to learn more about what’s causing the emotions, thoughts, or behaviors. It also helps them understand the best treatment plan for the individual moving forward.

Living With, Managing, & Treating ADHD

Understanding the individual’s brain structure, brain function, and genetic breakdown is essential when finding help for ADHD. Still, it doesn’t explain the many symptoms and warning signs individuals need to pay attention to — not just in themselves, but in their loved ones.

We briefly mentioned the three major symptoms earlier — inattentiveness, impulsivity, and hyperactivity. Let’s take a closer look at these three symptoms and what it’s like to live with them:

  1. Impulsivity – interrupting others, can’t wait your turn, blurting out answers to a question when you don’t know the answer, taking risks without thinking about it.

  2. Inattentiveness – short attention span, struggle to listen, can’t follow directions or details, easily distracted, often forget things, struggle with organization, and difficulty studying.

  3. Hyperactivity – can’t refrain from climbing or running around, can’t sit still, often fidgets with items, hands, feet, excessive talking, difficulty being quiet, and can’t stay on task for long.

Many people might be thinking to themselves, “I’ve experienced those symptoms before. Does that mean I have ADHD?” While it doesn’t mean you don’t have ADHD, it doesn’t necessarily mean you have it either.

To be considered, you first must have a minimum of six major symptoms of either inattentiveness or hyperactivity/impulsiveness. The DSM-5 has a total of nine symptoms listed in each category. There are several other criteria that must be met before a healthcare professional can diagnose you with ADHD.

Here’s a quick breakdown of the other criteria needed:

  • Several of the symptoms must’ve been present before the age of 12.

  • The symptoms must be present in multiple different settings (home, office, work, school, friend’s house, grocery store, library)

  • The symptoms need to have a clear impact on the individual’s ability to live a happy, healthy, or normal everyday life.

  • The symptoms can’t be a result of another mental health, behavioral, or emotional disorder.

Not all people living with ADHD suffer from all of those symptoms. There are three major subtypes of ADHD that help distinguish a person’s symptoms — predominantly inattentive type (ADHD-PI), predominantly hyperactive/impulsive type (ADHD-HI), and the combined type (ADHD-C).

Understanding the person’s subtype is a major step in the right direction when finding the right treatment plan for that individual. Since everyone has unique symptoms and everyone has a different experience with ADHD, it’s essential everyone receives unique treatment and care.

For some, that means medication; for some, that means therapy, and for some, it might mean a combination of both. Of course, you should always consult with a doctor before trying any of them, especially since symptoms can worsen with the wrong treatment.

While medication and therapy should be left to a professional, there is a wide range of tools and strategies for managing symptoms that are extremely safe for any individual — with or without ADHD. Here’s a quick look at those:

  • Following a daily routine helps your brain work less daily when completing everyday tasks. Eventually, your brain goes on ‘auto,’ which allows you to stay on-task better.

  • Find ways to live a more organized life. Keep your files and documents in a filing cabinet. Put your keys and wallet in the same place when you get home every day.

  • Chop long or big tasks into smaller and more manageable tasks. It not only helps you stay on-task, but you’ll give yourself frequent breaks to regroup.

  • Distractions are your worst enemy when living with ADHD, so minimize them whenever possible. Of course, that means you have to understand what your distractions are.

  • Utilize apps and calendars when managing your daily, weekly, and monthly tasks. Reminders are your best friend and help you forget less throughout the day.

  • Sleep is highly important to your daily routine. Ensure you go to bed at a reasonable time, receive a reasonable amount of sleep, and wake up at a reasonable time.

  • Understand your priorities every single day. Tackle what’s most important first and use lists to keep yourself on track with your schedule.

  • Learn when you need a break, learn what your limits are, and understand your symptoms. Awareness does more than anyone gives it credit for.

It doesn’t matter what your symptoms are or how long you’ve noticed the symptoms; you should always consult with a doctor the moment you realize something’s off in your life. They’ve spent their entire lives learning about people living with similar symptoms as you, and they can direct you to the right treatment plan, whether you have ADHD or not.