Why People with ADHD Often Forget What They Were About to Say

Have you ever started saying something and then—just like that—forgot what it was? For people with ADHD, this happens a lot. It’s not just being distracted or zoning out. The thought was there, and then it wasn’t. Gone.

This happens because of problems with working memory and executive function. These are the brain tools that help you hold on to thoughts, plan what to say, and keep your mind on track. In ADHD, those tools often don’t work as well.

As a result, ideas can vanish mid-sentence. You might pause, lose your place, or forget your point. But there’s a reason behind it. Let’s break down why this happens so often in ADHD.

Working Memory and Executive Function in ADHD

People with ADHD often forget what they were about to say because of issues with working memory and executive function.

These are two key brain functions that help you hold onto information and manage your thoughts and actions. But for people with ADHD, both of these functions tend to work differently—and sometimes less effectively.

According to a study, working memory is the ability to hold information in your mind and use it to guide your actions. Imagine it like a mental notepad that helps you remember what to say next or what step comes next in a task. In people with ADHD, this notepad is often unreliable. They might forget mid-sentence what they wanted to say, or lose track of their thoughts during a conversation. This happens because the information simply doesn’t stay in the brain long enough to be used. Individuals with ADHD often appear forgetful, disorganized, and struggle to stay on track because their working memory can’t keep up.

Further supporting this, one study found that children with ADHD performed significantly worse on working memory tasks compared to their peers. These difficulties were especially strong when they had to keep track of several steps or pieces of information at once. According to their study, this poor working memory was strongly linked with real-world problems, like forgetting school materials, missing steps in assignments, or struggling to organize tasks at home and school.

Working memory is just one part of executive function. Executive function also includes things like starting tasks, managing time, controlling emotions, and staying focused. ADHD can disrupt these executive functions, leading to delays in internal speech—what we call the “mind’s voice.” This is what helps you plan, remind yourself of goals, or stay on task. When this voice is delayed or weaker, it becomes harder to organize your thoughts or remember what you were going to say.

The ADHD brain works like predictive text. Your brain might jump ahead and feed you the next sentence before you’re finished with the current one. This results in disorganized thinking, where ideas pile up too quickly or vanish before you can express them. The brain moves faster than the mouth, and that mismatch can make you pause, forget, or derail mid-conversation.

Why Thoughts “Disappear” in ADHD

Some children with ADHD don’t just get distracted. Sometimes, their minds go completely blank.

According to experts, children with ADHD may stop having thoughts altogether during certain moments, leaving their minds empty. This isn't the same as daydreaming. While mind-wandering means the brain is still thinking—just not about the task—mind blanking means there’s nothing there to report at all.

To find this out, the authors studied 80 children aged 6 to 12. They divided them into four groups: 20 children with untreated ADHD, 20 with ADHD taking methylphenidate, 20 with other psychiatric conditions, and 20 neurotypical children. All the children did very boring tasks designed to be dull on purpose. During the tasks, the researchers randomly paused the activity and asked the kids what they were thinking.

Each time, the children had to choose from five categories:

1. On-task focus
2. Mind-wandering
3. Distraction
4. Task-related interference
5. Mind blanking

Surprisingly, the children with untreated ADHD were more likely to say they had no thoughts at all—just blankness. In contrast, neurotypical children and those with other psychiatric conditions rarely reported mind blanking.

Even more interesting, children who took methylphenidate had the same level of mind blanking as untreated children with ADHD. The medicine reduced mind-wandering, but not blank moments. This suggests that the brain systems for staying focused and letting thoughts flow may use the same “executive” resources. When those systems are weak, thoughts may become chaotic or break off entirely.

This could mean thoughts in children with ADHD are often shorter and harder to describe. Sometimes, they just disappear. This might explain why kids with ADHD sometimes seem confused or slow to respond—even when they’re trying hard.

They also looked at nonclinical adults—40 people total, 15 of whom reported ADHD symptoms. They found the same pattern. Those with ADHD traits had less mind-wandering and on-task focus, but more mind blanking. According to the researchers, this shows that these blank states can happen across different age groups.

These results raise a big question: Are the blank moments due to the brain truly stopping thought, or do people with ADHD just not notice or remember their thoughts?

Well, more research is needed to find out. Still, their findings help us better understand why people with ADHD sometimes seem to “freeze up.”

But maybe next time if someone with ADHD says, “I don’t know what I was thinking,” it might be because—at that moment—they weren’t thinking anything at all.

Reddit Discussion of Memory Lapses in Conversation

According to user Alyssinreality on Reddit, this type of memory lapse feels like thoughts are constantly slipping through a strainer, not a bucket—information just doesn’t stick. This metaphor shows the constant mental drain many individuals feel when trying to hold on to what they’re thinking.

One user, Plusran, explained it clearly by saying, “Distractions erase my working memory.” A simple distraction can completely wipe out what they were about to say. They gave an example: walking into a room and immediately asking themselves, “What was I doing? Why am I in this room now?” That moment of complete blankness can feel like hitting a wall.

Another user described the pattern as, “Think thought. Think new thought. Forget old thought.” This reflects how fast new thoughts replace old ones before there's time to finish or speak them. In this fast cycle, conversations can be hard to follow, especially when jumping from one topic to the next.

According to oodoov21, one way they manage this issue is by writing everything down, including ideas and important parts of conversations, because otherwise, the thoughts vanish. Without a written record, they can't bring the original thought back, even minutes later. This person uses a digital note-taking system synced between their phone and computer just to stay on track.

So what’s really happening here? These examples point to weak working memory—a common struggle in ADHD, especially the inattentive type. As Broad_Commission_242 mentioned, their long-term memory was fine, and short-term memory was okay, but working memory was the problem. Tasks that needed thoughts to be held in the mind, even briefly, became very difficult.

Final Words

Weak working memory and executive function make it hard to hold on to ideas. Thoughts can slip away before they’re spoken. In some moments, the mind goes completely blank, leaving nothing to say at all. This happens in both kids and adults with ADHD.

This is not rudeness or distraction—it’s actually the brain working differently. And sometimes, the thought really is just… gone.

Frequently Asked Questions

What’s the difference between mind-wandering and mind-blanking?

Mind-wandering means your thoughts drift to something else. Mind-blanking is when your brain just...stops. Kids with ADHD often report this blank state—no thoughts at all.

Can ADHD make your mind go completely blank?

Yes. Kids with ADHD often report “mind blanking” instead of wandering thoughts. It's like their brain hits pause, especially during boring tasks.

Do ADHD meds stop the blanking?

Not exactly. Meds like methylphenidate help with focus and reduce mind-wandering, but they don’t seem to change the blank moments much.

Is ADHD caused by bad parenting or too much sugar?

Nope. ADHD has strong biological roots. Genes play the biggest role. Other factors like low birth weight or brain injury can also increase risk—but sugar and screen time aren’t causes.