What Are Executive Functions, and Why Are They Hard in ADHD?

There is a day I remember, when I sat for three hours in front of a report. I knew what to write. I knew how it should be written. I even wanted to write it, because I knew what would happen if it was not handed in.

Three hours later the document was still empty, and that day I told myself "you're lazy."

I learned much later that the gap had a name. "Executive function" is one of the terms that appear most and are explained least in ADHD texts. It is not a measure of intelligence; it is a management team.

Who is on the team

Executive functions are not a single skill but the shared name of several separate jobs:

• Task initiation. Being able to make the first move. The step ADHD trips on most.
• Inhibition. Being able to stop an automatic reaction. This is the function at the center of Barkley's theory (Barkley, 1997).
• Working memory. Being able to hold the necessary information in mind while doing a job.
• Planning and sequencing. Dividing a goal into steps and putting them in the right order.
• Time estimation. Judging how long a job will take.
• Cognitive flexibility. Being able to change behavior when the rule changes.
• Task persistence. Staying with a job once it has started.
• Self-monitoring. Noticing your own behavior as you do it.

Brown defines ADHD as exactly the disorganized working of this cluster and says that the name "attention deficit" is misleading (Brown, 2005).

Why "knowing" is not enough

This is the most misunderstood side of executive functions. The person knows what they should do, knows how it is done, and wants to do it. What stands in between is execution.

This is called the intention-behavior gap. From outside it looks like laziness or indifference; from inside it is something quite different.

An executive function problem is not not knowing what to do. It is not being able to do what you know.

How strong the evidence is

I do not want to skip this part, because the sentence "ADHD is an executive function disorder" is put very often and very firmly.

The meta-analysis by Willcutt and colleagues, which combined 83 studies, found that ADHD groups struggled significantly on all the executive function tasks measured. The effects were moderate; the most consistent appeared in measures of response inhibition, vigilance, working memory and planning (Willcutt et al., 2005).

The second result of the same meta-analysis is cited less and is, I think, more important: this difficulty is not seen in everyone with ADHD. The authors' conclusion is that executive function weakness is neither necessary nor sufficient to explain all cases of ADHD. It is an important part of a complex picture, not the whole of it.

So this framework helped me a great deal in explaining myself to myself; but it cannot be read as "you have ADHD, so you must score low on tests." Getting a normal result on neuropsychological tests does not rule out ADHD.

Why it looks inconsistent

The same person works perfectly one day and can do nothing the next. This inconsistency is the most judged side of ADHD, because it invites the sentence "so you can do it."

The reason is this: executive functions are very sensitive to arousal level, sleep, interest and stress. In a job that holds interest the team works flawlessly; in a boring job it never switches on. Skill fluctuation comes from here.

In me this shows most with sleep. On a day after five hours of sleep half the team does not come to work, and everything I do that day takes twice the effort.

How it looks in daily life

As long as the term stays abstract it is no use. For me the counterparts are these:

Initiation. Standing in front of the dishwasher and being unable to begin emptying it. The job is ten minutes, the standing is forty.

Working memory. Forgetting why I walked into a room. Or losing two of the three things I was going to say while on the phone.

Sequencing. Being unable to work out, while cooking a meal, which job has to start first; everything is not ready at the same time.

Time estimation. Saying "this job takes half an hour" and spending three hours. There is the reverse too: though I have gone the same road for years, I still do not know how long it takes.

Cognitive flexibility. Being unable to build a new plan when my plan falls through; the two hours freed by a cancelled meeting being no use for anything.

Self-monitoring. Not noticing in the moment that I am going on too long and the person in front of me is bored, and noticing in the evening.

When I made this list I got less angry with myself. In place of a muddled feeling of "I can't do it," came six separate jobs, each of which could be handled on its own.

How it is supported

It does not seem possible to "strengthen" executive functions directly; in computer-based exercises the person improves at that exercise but the transfer of the gain to daily life stays limited (Faraone et al., 2021). What works is doing the job from outside:

• Visible lists. Handing the holding in mind over to paper. I described the one-list rule in the article on the one list.
• Audible timers. Seeing time instead of feeling it.
• If-then plans. Deciding in advance in the form "if this happens, I will do that" removes the load of on-the-spot decisions; this is called an implementation intention, and plans formed this way turn into behavior at a markedly higher rate (Gollwitzer, 1999).
• Fixed places. An object having a known place means the environment takes over the work of remembering; I wrote about the order I set up in the article on the visible place system.
• Outside accountability. A person you have promised, an appointment, a deadline. The simplest form of this is body doubling.

The common name for all of them is external scaffolding: building from outside the internal structure that is missing. It is like wearing glasses, not a trick.

I will add a warning too, because reading this list it is very tempting to try to set up all of it at once. At the end of the weeks when I set up five systems at once, I had no system left. Choosing one and keeping it for six weeks changes far more than keeping five for a week. The system itself is also an executive function job; the upkeep of what you build must be light enough for you to carry.

Find out which step you are stuck on. The sentence "I can't do it" is very broad and leads to no solution. Divide the job into eight steps and mark where you stop: can't you start, can't you set the order, do you get lost after starting, or do you leave it at ninety percent? The solution for each step is different, and a solution applied to the wrong step does not work at all.

What knowing this changed

On its own it solved nothing. There are still jobs I cannot start, I still estimate time wrongly.

What changed was the kind of solution I look for. I used to look for more willpower for myself; now I build better scaffolding for myself. The first ended every time in blaming me. The second gives me a job to do.

For those three hours I spent in front of that empty document I no longer say "I was lazy." I say "I got stuck at the initiation step and I had no tool for that step." A tool can be found; character cannot.