ADHD: Why Am I Like This?Part 14: Mental Load and Executive Fatigue

By this point in my investigation, I had stopped asking whether my brain worked differently.

The evidence was overwhelming.

A different question had begun to emerge.

Why could I spend an entire day sitting at my desk...

...and still feel as exhausted as if I'd spent the day doing physical labor?

That became another clue.

"I Didn't Even Do Anything Today."

I've said those words more times than I can count.

I'd spend the day writing.

Researching.

Planning.

Problem-solving.

Answering emails.

Trying to decide what deserved my attention next.

Then evening would arrive.

I'd feel mentally drained.

Yet I'd look around the room and think,

"I didn't even do anything today."

That conclusion never seemed fair.

But it felt true.

For years, I assumed exhaustion had to be earned through physical work.

The Invisible Work

Looking back, I realized my brain was rarely doing just one thing.

Even while writing this chapter...

Part of my attention is choosing the next sentence.

Another part is wondering if I've already made this point somewhere else in the book.

Another is remembering a research paper I read three weeks ago.

Another is trying not to forget an idea I want to include later.

Another is deciding whether this paragraph should stay or be deleted.

None of that work is visible.

But all of it requires energy.

What the Research Says

As I dug deeper, I discovered that researchers often describe ADHD as a disorder of executive functioning.

Executive functions aren't a single ability.

They're the brain's management system.

They help us plan.

Prioritize.

Shift attention.

Hold information in working memory.

Resist distractions.

Monitor mistakes.

Decide what to do next.

For many people with ADHD, those processes require significantly more conscious effort.

Researchers have found that tasks others complete almost automatically often demand much more active mental work from people with ADHD.

That immediately resonated with me.

Perhaps I wasn't becoming exhausted because I lacked stamina.

Perhaps my brain was simply working harder behind the scenes.

Too Many Programs Running

The best analogy I've found is a smartphone.

You lock the screen.

The phone appears to be doing nothing.

Yet dozens of applications continue running quietly in the background.

Each one consumes a little memory.

A little processing power.

A little battery.

Eventually...

The battery runs low.

Nothing dramatic happened.

Too many things were simply running at once.

That's often how my brain feels.

Not overwhelmed by one enormous problem.

Exhausted by hundreds of tiny invisible ones.

When My Mind Never Went Home

Looking back, I can see one period of my life that illustrates this better than any research paper ever could.

During the years leading up to my divorce, I was renovating a house for my children and me while trying to navigate the uncertainty of a marriage that was ending.

Every unfinished room represented another decision.

Every repair represented another project.

Every legal document represented another unknown.

The house wasn't the only thing under construction.

So was my future.

On top of this, my mother had a massive stroke and I had major concerns about the quality of her care.

I became exhausted.

Not the kind of exhaustion that follows physical labor.

The kind that makes getting out of bed feel overwhelming.

The kind that quietly begins to resemble depression.

Looking back, I don't think I was physically worn out.

I think my brain had been fighting for survival.

Every unfinished project.

Every unresolved question.

Every uncertain outcome.

They were all running quietly in the background, consuming attention and energy whether I wanted them to or not.

Perhaps the greatest drain on my energy wasn't the work I was doing.

It was the work my brain refused to stop doing.

Then something remarkable happened.

The divorce was finalized.

Any input I had on my mother's care was completely taken out of my hands and rejected.

The uncertainty ended.

The background programs slowly began shutting down.

In the months that followed, I accomplished more than I had during the previous three years combined.

Not because I suddenly became more motivated.

Because my mind finally had enough room to dream again.

For the first time in years, I wasn't mentally fighting for my life.

I could finally relax enough to imagine a future instead of merely surviving the present.

That became one of the biggest clues in my entire investigation.

What I've Learned

For years, I believed I hadn't accomplished enough to justify feeling tired.

Now I think I misunderstood what had been exhausting me.

I wasn't measuring the work my brain had actually done.

I was measuring only the work other people could see.

Just because mental work leaves no sweat doesn't mean it costs no energy.

Just because no one watches you make thousands of tiny decisions doesn't mean they aren't happening.

I've stopped apologizing for needing rest after a day of sustained thinking.

I've also stopped assuming that rest has to be earned through physical labor alone.

Sometimes the most demanding thing I do all day is think.

That realization has changed how I plan my days.

I've learned to schedule recovery the same way I schedule work.

I take daily breaks to exercise.

Read something just for pleasure.

Go to the beach.

Spend time with my dog.

Sometimes I simply allow my mind to be quiet by playing a video game or watching a show.

Not because I've given up.

Because even a well-designed machine needs to cool down.

For years, I judged my energy by what I accomplished.

Now I try to judge it by what my brain actually had to process.

Just because your work is invisible doesn't mean it isn't exhausting.

That realization changed more than the way I think about fatigue.

It changed the way I think about rest.

More importantly...

It changed the way I think about myself.

The Next Clue

As my investigation continued, another question quietly emerged.

If understanding my brain has changed the way I work...

...what has it changed about the way I see my past?

How much of my life have I spent judging myself unfairly?

That became another clue.

Next

Part 15: Mislabeled

References

Barkley, R. A. (2012). Executive Functions: What They Are, How They Work, and Why They Evolved. Guilford Press.

Barkley, R. A. (2015). Attention-Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment (4th ed.). Guilford Press.

Brown, T. E. (2013). A New Understanding of ADHD in Children and Adults: Executive Function Impairments.Routledge.

Faraone, S. V., Banaschewski, T., Coghill, D., et al. (2021). The World Federation of ADHD International Consensus Statement: 208 Evidence-Based Conclusions About the Disorder. Neuroscience & Biobehavioral Reviews, 128, 789-818.

Willcutt, E. G., Doyle, A. E., Nigg, J. T., Faraone, S. V., & Pennington, B. F. (2005). Validity of the Executive Function Theory of ADHD: A Meta-Analytic Review. Biological Psychiatry, 57(11), 1336-1346.

Brown, T. E. (2006). Executive Functions and Attention Deficit Hyperactivity Disorder: Implications of Two Conflicting Views. International Journal of Disability, Development and Education, 53(1), 35-46.