ADHD and Perimenopause, Part 1: Is It Brain Fog or Something More?

There has been a lot more conversation lately about ADHD and brain fog during perimenopause. It seems to be everywhere, podcasts, social media, articles, and conversations in the midlife space. This information is great, but it has a lot of women even more confused about symptoms of brain fog and many are wondering whether what they have always thought of as perimenopause brain fog could actually be something more.

We have known for a long time that women can notice changes in memory and concentration during perimenopause. You may not feel as sharp as you used to. You may lose your train of thought, forget why you walked into a room, have trouble finding the right word, or notice that things that used to come easily suddenly take more effort.

We are now  talking more about another question: Could some women actually have ADHD that was never recognized before?

For years, there just wasn't a lot of research looking at how the brain is affected during perimenopause and menopause.There also wasn't much research on how ADHD shows up in women. So if you are a woman going through perimenopause who also has ADHD, you've been caught in the middle of two areas medicine didn't pay much attention to. Thankfully, that is starting to change. Researchers are finally studying both, and they are just starting to look at how the two are related.

Perimenopause does not cause ADHD. ADHD starts earlier in life, usually in childhood. Yet the hormone changes of this transition can affect concentration, memory, and executive function. Executive function is the set of skills we use to plan, stay organized, focus, and get things done. For women who already know they have ADHD, these changes can make symptoms harder to manage. For women who have gone their whole lives without a diagnosis, perimenopause may be when the strategies they have always relied on stop working as well.

That doesn't mean every woman with brain fog in perimenopause has ADHD. Plenty of women have true changes in focus and memory during this time without having ADHD at all. 

This is Part 1 of a series. In Part 1, I describe what is happening in the brain during perimenopause, why ADHD can become more noticeable, and how to tell brain fog apart from ADHD. In Part 2, I describe the emotional side of ADHD, treatment options, and how to talk with your healthcare provider.

Why Am I Suddenly So Forgetful and Unfocused in My 40s?

Brain fog is a term that is often used, and it can mean different things to different people.

Along with the examples above, here are some other ways my patients describe it. They know the word they want to say, but they just can't find it. They read a page and then realize they didn't take in any of it. They forget appointments, and they are always looking for their phone.

For some women, it's more than memory. They have a hard time deciding what to do first. They know what needs to get done but have trouble getting started. A workload they handled without much trouble a few years ago now feels overwhelming.

One thing I hear a lot is that they can still sing every word to a song from high school, but they can't remember where they put their keys five minutes ago.

Brain fog alone doesn't make me think of ADHD. But if a woman tells me she has dealt with procrastination, disorganization, or distraction for most of her life, that's when I start to wonder.

Why ADHD Gets Missed in Women

When I was growing up, and even during my training, we mostly thought of ADHD as something children had. We usually thought of a young boy who couldn't sit still in class and was always on the go, and some children with ADHD do look like that, but many don't.

Thankfully, we have learned a lot more and now know that ADHD doesn't always mean being restless or overly active. We also know that most people don't simply outgrow it. In adults, ADHD can look like trouble focusing, staying organized, managing time, finishing tasks, remembering things, or feeling overwhelmed when there is a lot going on.

This is one reason ADHD can be missed in girls. Many were quiet, daydreamed, lost things, or had trouble staying organized. Some worked extra hard just to keep up, and many made good grades. Since everything looked fine on the outside, ADHD wasn't necessarily something anyone thought to look for. Symptoms can also overlap with anxiety and depression, which can make it even harder to recognize.

How ADHD Can Go Unnoticed for Years

Some of those girls grow up and become women who figure out their own ways to manage these challenges. They may build very detailed systems to stay organized without ever realizing why they need them.

Maybe you check your work over and over because you're afraid you missed something.

Maybe you live by calendars, alarms, lists, sticky notes, and reminders. You may stay late to prepare for the next day, feel like everything has to be perfect so you don't make a mistake, or find that you do your best work when you're up against a deadline. From the outside, you may look completely put together. What other people don't see is how much work it takes to keep everything that way.

These strategies may work really well for years and then perimenopause comes along, and suddenly they may not work as well as they used to. The ADHD didn't start with perimenopause. It may have been there all along, but it just wasn't recognized.

Research is showing us how often ADHD is diagnosed later in women. In one large U.S. study of more than 13,000 adults with ADHD, those diagnosed in adulthood were, on average, in their mid-40s, and about 3 out of 4 were women (Leffa et al., JAMA Network Open, 2026). That helps us understand why some women can get well into adulthood before ADHD is ever considered.

How Estrogen Affects Focus

Most people think of estrogen as a reproductive hormone, but it does a lot of work in the brain too. Estrogen also affects dopamine, one of the brain chemicals involved in focus, motivation, organization, and getting things done.

Estrogen helps the brain make dopamine, and it also helps dopamine stick around longer once it's there, so more of it is available when you need to focus. During perimenopause, estrogen doesn't fall in a straight line. It can rise and drop, sometimes sharply,  not just from month to month, but even from day to day. When estrogen dips, dopamine can also dip with it and for a brain already wired toward ADHD, that can mean more trouble with focus, organization, motivation, and keeping emotions steady. Our brains can be sensitive to these hormonal ups and downs.

This doesn't mean every focus problem in perimenopause is ADHD. Perimenopause can cloud thinking all on its own. However, it may help explain why a woman who has managed her ADHD pretty well for years suddenly finds that the things she has always done aren't working as well anymore.

What Is Executive Function?

One of the things that helped me better understand ADHD was learning more about executive function, the skills our brain uses to plan, organize, prioritize, and get things done.

Think about trying to get out the door in the morning. You know what time you need to leave, but you also have to get dressed, remember what you need for the day, answer that email you forgot about, find your keys, maybe pack a lunch, and make sure you leave enough time to actually get where you're going. Most of us don't think about how much planning and organization our brain is doing behind the scenes to make all of that happen.

When executive function is harder, you can know exactly what you need to do and still have trouble getting started. You may start several things but not finish them, have trouble deciding what needs to be done first, put off something that should be pretty simple, or completely underestimate how long something is going to take.

For some women with ADHD, a deadline is what finally gets things moving. And when you're constantly having to work this hard to organize and stay on top of everyday life, it can be exhausting.

Perimenopause Brain Fog or ADHD?

There can be a lot of overlap between the two, and no checklist can tell you for sure which one is going on but looking back at your history can give us some important clues.

With perimenopause brain fog, the changes often feel newer. Maybe you have always been pretty organized and able to focus, but lately it is taking more effort. You may be more forgetful, have trouble finding words, or find it harder to concentrate. These changes may also be happening along with other symptoms of perimenopause, like hot flashes, night sweats, or disrupted sleep.

With ADHD, there is usually more of a history. Maybe you have always been easily distracted or staying organized has always taken extra effort. Maybe you tend to procrastinate, start things and not finish them, or find that you get the most done when you are up against a deadline. You may have figured out ways to manage all of this over the years, so you never really thought much about it.

One of the biggest clues is the timeline. Were some of these same patterns there long before perimenopause?

Could ADHD Have Been There All Along?

It helps to look back honestly. Were you easily distracted as a kid? Did you procrastinate but still pull good grades? Were you always losing things? Then look at your adult life. Do you lean hard on lists and reminders just to stay afloat? Do projects stall the moment they stop being interesting? Has staying organized always felt harder for you than for the people around you? Have you looked like you had it together on the outside while feeling scattered on the inside?

If you look back and recognize some of these same patterns throughout your life, that's important to share with your clinician.

Family history can also give us a clue. ADHD tends to run in families, and research shows that genetics play a significant role (Faraone and Larsson, Molecular Psychiatry, 2019). In fact, some women first start recognizing these same patterns in themselves when one of their children is being evaluated or diagnosed with ADHD.

Frequently Asked Questions

Can you be diagnosed with ADHD for the first time in your 40s? Yes. A diagnosis can come in midlife even when the pattern started in childhood.

Can you have ADHD and perimenopause brain fog at the same time? Yes. They can overlap, which is one reason a good evaluation matters.

What's the biggest clue that ADHD may be involved? Your history. Look for similar struggles with attention, organization, or procrastination earlier in life.

Coming Up in Part 2

In Part 2, I'll talk about the emotional side of ADHD, how symptoms can shift across your cycle, what treatment can look like, and how to start the conversation with your healthcare provider.