Is Forgetfulness Normal in ADHD?

I go to the kitchen, I stand in front of the door and I do not know why I came. It happens at least twice a day. Before the diagnosis I took this very seriously; I would think, "can a person be this forgetful at twenty-three?"

Now I know that this forgetfulness is counted among the diagnostic criteria of ADHD. In other words, it stands not as a side feature but as part of the picture.

But this answer has a dangerous side as well as a reassuring one: writing every bit of forgetfulness off to ADHD can lead to overlooking something that needs to be explained. In this article I will deal with both.

What kind of forgetfulness this is

The distinction is here: forgetfulness in ADHD does not work like a recording problem. Memories are not erased. What is strained is the capacity to hold information in mind for a short time and work on it.

The study by Kofler and colleagues (2010) shows that working memory capacity is measured as more limited in ADHD. The meta-analysis by Willcutt and colleagues (2005), which combined 83 studies, also reveals consistent differences in executive function measures. The effect sizes remain moderate; that is, these tests are not used alone as a diagnostic tool, they serve to describe the picture.

In daily life it looks like this:

• Walking into a room and forgetting why you came in.
• Losing what you were going to say in the middle of a sentence.
• Starting another job while holding something in your hand and leaving the first one where it is.
• Not remembering the paragraph you just read.
• Building your answer while someone is talking and missing what they say in the meantime.

The last is the most frequent in me and the most embarrassing. Because from outside it looks like not listening, whereas the effort of listening itself drops the information. I described this mechanism in detail in the article on working memory and forgetfulness.

The information is not lost. The hand holding it lets go when it reaches for something else in between.

The area that falters most

Its name is prospective memory: the ability to remember to do something in the future.

This is where ADHD falters most, and it is also the one with the highest daily cost:

• Remembering to pay the bill.
• Remembering to take the medication.
• Doing what you promised on time.
• Going to the appointment.

The difficulty here is not not knowing the information. It is not being able to bring the information up at the right moment. I know the bill exists, I know its due date too; what I do not know is whether it will cross my mind on the day that date arrives.

That is why the sentence "if you forgot, it means you don't care" hurts me so much. Caring and remembering are different systems, and I forget the things I care about too. Sometimes even the ones I care about most, because I forget to do them out of thinking about them.

When to be worried

This is the most important part of the article and I do not want it skipped.

Typical features of forgetfulness linked to ADHD:

• It has been there since childhood.
• It does not get markedly worse over time.
• It increases with fatigue, stress and sleeplessness, and decreases with rest.
• It is seen far less in subjects you are interested in.

Signs that call for seeing a doctor:

• If the forgetfulness started recently and was not like this before.
• If it is getting worse quickly.
• If there are symptoms such as losing your way in familiar places or not recognizing familiar people.
• If there is a marked and new difficulty finding words.
• If those close to you notice the change more than you do.

There are other treatable causes too, and they are often overlooked: thyroid dysfunction, B12 and iron deficiency, sleep apnea, depression, side effects of some medications.

So the answer "I have ADHD" is not enough to explain a forgetfulness that has newly started. Having been diagnosed does not mean nothing else is going on, and I need to remind myself of this too.

The change itself is information. What is decisive here is not the degree of the forgetfulness but its course. If it has always been this way, that is a pattern; if it appeared in the last six months, that is a change, and changes deserve to be evaluated.

What helps

The logic that works here is to stop trusting memory rather than trying to strengthen it. For years I tried the opposite: I tried to pay more attention, to focus more. None of it held, because the problem was not in the effort.

Everything in one place. Someone who keeps two lists trusts neither and carries the load in their head anyway. I described it in detail in the article on the one-list rule.

Write it the moment it comes to mind. The sentence "I'll write it later" means having to keep remembering that thing for a while longer. The rate at which the things I said "I'll write later" got lost in me is almost one hundred percent.

Keep it in a visible place. What goes into a cupboard disappears. The reason is object permanence and the solution is to bring the thing to eye level. Details in the article on the visible place system.

Automate. An automatic instruction for recurring payments, a calendar for recurring appointments. A system set up once is much cheaper than a job remembered anew every month.

A single entry point. Keys, wallet and card in one place. This rule alone halved the time I spend searching. I dealt with the mechanism of losing things in the article on losing things.

Tie the reminder to an action, not to a time. When a reminder "bill at 8 p.m." arrives while I am doing something else, I dismiss it and forget. A link like "bill when I get home" holds better, because it rides on a movement I am going to make anyway.

Tie unfinished work to a plan. Even for a job you cannot finish, writing when you will do it reduces the room that job takes up in the mind.

A common mistake: abandoning the system on the day you forget it

This was my biggest mistake. The system would work for three weeks, one day I would forget to look at the list, and I would say "so this didn't hold either" and drop it.

Yet no system works one hundred percent. A system that works eighty percent is incomparably better than no system. The day you missed should not be counted as the system's bankruptcy; it should be read as part of how the system normally runs.

Now I think like this: on the day I forget to look at the list, the list does not save me. But on the thirty days I look, it does, and those thirty days gain me a great deal in total.

The shame part

The heaviest side of forgetfulness is usually not the thing forgotten. It is what you say to yourself after forgetting.

The World Federation consensus statement (Faraone et al., 2021), while setting out the broad effects of ADHD on functioning, includes this secondary load in the picture too. That is, the result is not only missed appointments; what you say to yourself after missing them also counts.

I dealt with this side in the article on shame and self-compassion in ADHD.

When I notice I have forgotten something, I now ask one question: can I set up a mechanism that will prevent this from happening again? If the answer is yes, I set it up. If no, I move on. There is no step set aside in between for being angry at myself, and removing that step helped me more than the lists did.