When I was diagnosed with ADHD-Inattentive at 34, I thought ADHD was a single thing: the classic image of a hyperactive kid bouncing around a classroom. Then I started researching and realized ADHD isn’t one-size-fits-all. There are three presentations, and they can shift over time. My ADHD may not look like someone else’s, but that doesn’t make either one less valid.

Quick note before we go further: I’m not a mental health professional. What I share comes from personal experience and trusted research. If you think you might have ADHD, talk to a licensed clinician.

The Three Presentations of ADHD

According to the DSM-5-TR, there are three official presentations of ADHD:

  • Predominantly Inattentive: Trouble focusing, organizing, and following through.
  • Predominantly Hyperactive-Impulsive: Restlessness, fidgeting, impulsive decisions, and interrupting.
  • Combined: A mix of both inattentive and hyperactive-impulsive symptoms.

Presentations can evolve over time. For example, what looks like hyperactivity in a child might become mental restlessness or constant internal motion in an adult. You can learn more about how ADHD changes with age from the CDC’s overview.

How the Types Show Up for Adults

Group of diverse adults with ADHD working together at a creative planning table covered in colorful sticky notes, representing collaboration, executive function strategies, and adult ADHD productivity tools. Reflects how people with different types of ADHD—Inattentive, Hyperactive-Impulsive, and Combined—use teamwork and structure to manage focus and achieve goals.

Inattentive ADHD

This is the most common form in adults and in women. Research estimates that about 3.1% of adults worldwide have ADHD (Psychiatry Research, 2023). People with this type often deal with forgetfulness, zoning out, losing track of time, and difficulty finishing what they start.
Dr. Russell Barkley’s research shows that up to 95% of people with ADHD experience executive function challenges: things like planning, organization, and emotional regulation (MedPsych Health, 2025).

Hyperactive-Impulsive ADHD

This presentation is more common in children and in men, though it still shows up in adults. The outward fidgeting of childhood often becomes internal restlessness in adulthood. Interestingly, women with ADHD are more likely to experience “verbal hyperactivity,” according to a 2025 study of over 2,200 adults.

Combined Presentation ADHD

Many people fall into this category, especially during childhood. Combined presentation means you experience both inattentive and hyperactive-impulsive symptoms. ADDitude Magazine’s breakdown provides relatable examples that can help you identify where you might fit.

Why So Many Adults Miss Diagnosis Until Later

Three big reasons stand out:

  1. Childhood symptoms were overlooked. About 75% of adults with ADHD were never diagnosed as kids (PMC, 2021).
  2. Gender bias. Girls are more likely to have inattentive ADHD, which doesn’t always look disruptive, so they’re often missed or diagnosed later.
  3. Time blindness. A 2021 review found that time perception issues, feeling like time either flies by or doesn’t move at all, are a core part of ADHD (PMC, 2021).

My Personal Experience

When I finally learned about the different ADHD types, everything clicked. I wasn’t lazy or unmotivated, I had ADHD-Inattentive. My executive function struggles explained the disorganization, procrastination, and forgetfulness that followed me for years.

I also learned that hyperfocus, the ability to fixate intensely on one thing for hours, isn’t the opposite of ADHD. It’s part of it. A 2024 study showed that hyperfocus is linked directly to executive function differences, which helped me understand why I can edit a podcast for hours but forget to eat dinner.

What You Can Do Next

Close-up of a smartphone screen showing multiple morning alarms set five minutes apart, symbolizing adult ADHD time blindness, difficulty waking up, and the need for external systems to manage routines and executive function challenges.
  1. Take note of what’s hardest for you. Maybe it’s time management, emotional regulation, or follow-through.
  2. Seek a proper evaluation. Look for a psychologist, psychiatrist, or primary care provider experienced in adult ADHD. CHADD and ADDA are excellent places to start.
  3. Explore treatment options. A 2025 Oxford review found that stimulant medications and atomoxetine are the most effective for reducing ADHD symptoms.
  4. Build systems that support your brain. Use alarms, visual checklists, shared calendars, and time-blocking.
  5. Address emotional patterns. Learn about Rejection Sensitive Dysphoria (RSD) if intense emotions are part of your experience.

Quick Q&A

Q. What happened to the term ADD?
A. The DSM replaced it in 1994. What was once “ADD” is now called ADHD-Inattentive Presentation.

Q. Can your ADHD type change over time?
A. Yes. Many people shift from hyperactive or combined types in childhood to inattentive in adulthood.

Q. Is one type more severe than another?
A. No. Each affects different areas of life. What matters most is how much your symptoms interfere with daily functioning.

A Helpful Next Step

If this topic resonates with you, check out my digital guidebook:
“Navigating ADHD & Adulthood: A Digital Guidebook Full of Tools, Truths, and Support.”

It’s 53 pages of practical strategies, real talk, and lived experience, designed for adults figuring out their ADHD in real time.

You can also visit my Mental Health Resources Hub for more trusted tools and links.

Much love. Good vibes. – Ky