That stereotype is an oversimplification at best and entirely inaccurate for millions of people with ADHD at worst. In fact, emerging research shows that one of the most prevalent symptoms of ADHD is not excess energy but the lack of it in the form of mental fatigue.

What Is Mental Fatigue?

Mental fatigue refers to a feeling of cognitive and emotional exhaustion that manifests as feeling too tired to think. Any kind of cognitive effort from responding to a text message to deciding what TV show to watch becomes impossibly overwhelming. Your motivation to complete tasks, even ones you’d normally be excited about or at least comfortable with, is all but nonexistent. Temporary episodes of mental fatigue can happen to anyone after a period of intensive mental effort. Just like physical exercise makes you physically tired, mental exercise makes you mentally tired. While it can happen to anyone, people with ADHD are more likely to experience it and specifically, more likely to experience it on a frequent or chronic basis. One study found that as much as 62% of people with ADHD meet the criteria for fatigue. Similarly, another study found that people with chronic fatigue were more likely to also have an ADHD diagnosis.

Researchers suspect that the reason mental fatigue is so prevalent in ADHD may be related to how cognitively demanding coping with ADHD is. While a neurotypical brain is wired to intuitively tune out environmental distractors, control impulses, and sustain attention, many of the mechanisms required to do those things are dysregulated in ADHD, including weak alpha wave modulation and a dysregulated dopaminergic system. The result is that someone with ADHD is exerting more cognitive effort to achieve the same level of productivity that someone without ADHD can achieve almost effortlessly. That extra effort exerted every single day makes someone with ADHD prone to become fatigued more often and seemingly without a clear “justification” for being exhausted.

Some of the most common symptoms of mental fatigue look eerily similar to ADHD:

Lack of focusDifficulty making decisionsForgetfulnessDecreased productivityLack of motivationPoor emotional regulation, which can look like sudden outbursts, irritability, and mood swingsDaytime tiredness (or feeling like you’re already exhausted from the moment you wake up)

Given how closely those symptoms mirror ADHD, how can you tell the difference between your everyday, garden-variety ADHD-induced executive dysfunction and an episode of mental fatigue? One clue is that your typical ADHD symptoms become worse than usual. Beyond that, you might experience some of these more ADHD-specific signs of mental fatigue:

Struggling to fall asleep even though you’re exhausted Medication and coping strategies that usually help seem less effectiveNegative thoughts and low self-esteem become even worse than usualMental fatigue is prolonged or frequently recurring

Another telltale sign of ADHD-related mental fatigue is the lack of a specific stressor or source of this current episode of fatigue. For people without ADHD, the fatigue is usually brought on by a situation that demands more cognitive effort than usual: an unusually large or difficult workload, an emotionally challenging event like a death or a painful breakup, or a change in circumstances that makes your current responsibilities more difficult like having children or a pandemic that forces you to adapt to a new working routine. While all of those can certainly trigger fatigue in someone with ADHD, too, you may also experience episodes that seem to come out of the blue. Again, coping with ADHD is cognitively demanding so even when nothing about your daily routine or responsibilities changes, the exhaustion of managing your ADHD can accumulate until it develops into mental fatigue.

Recovering from Mental Fatigue

With mental fatigue, there’s really only one thing you can do: rest and allow your brain to restore its energy levels. With that said, resting with ADHD is easier said than done, especially if you have sleep difficulties. So here are a few tips to help you get the rest you need:

Do a physical activity

If you’re feeling too anxious or unproductive to sit still and rest, try going for a walk or bike ride. Physical exercise can help your brain recover from fatigue and potentially make falling asleep easier come bedtime, which will further help restore energy levels.

Ask for help

If fatigue is making it difficult to meet even basic needs like feeding yourself, doing household chores, or even caring for your kids or pets, ask for help with those tasks. Knowing that those important needs are getting met, even when you can’t do them yourself, can help ease some of the worry you might be feeling. If the thought of asking for help makes you feel like a burden, try easing that guilt by reassuring the person that you can do the same for them later when they need support. Everyone gets overwhelmed now and again, so there’s bound to be an opportunity to repay the favor.

Get outside or take some space for yourself to practice mindfulness

If you’ve hit a wall, staring at the unfinished work isn’t going to change anything. Step away and get outside if you can. Don’t bring your phone with you. Try practicing mindfulness to focus on your present surroundings and your present feelings. Name what you see and what you’re feeling right now, physically and psychologically. If your brain is trying to spiral into negative thoughts about the future or turn this moment into a sign that you’re a failure, do your best to not fixate on those thoughts. Let them pass through and try to return to your focus on the present moment.

Switch to low power mode

If you can’t take a complete break from all of your responsibilities, find ways to switch into a “low power mode” where you temporarily take some things off your plate so that what little energy you can muster is being spent on the most important tasks. That might include asking for help with certain chores or responsibilities. It might also look like stockpiling ramen or leftover takeout food so you don’t have to cook, canceling plans, and giving yourself permission to slack on some chores.

Preventing Mental Fatigue

When you have the bandwidth for it, it’s helpful to adopt some lifestyle changes that can prevent you from reaching that point of mental fatigue in the first place. Here are some things to try:

Reduce decision-making and steps where possible

We make thousands of little decisions every day and the cumulative effort of those decisions adds up, especially when executive dysfunction makes even basic decisions difficult. To prevent exhaustion, find creative ways to eliminate decisions where you can. For example, make a to-do list for the day, with tasks separated into high priority, medium priority, and low priority columns, (or separated by how much anxiety you feel about the fact that the task isn’t done yet). When you can’t figure out where to start or what to do next, just pick a column you want to focus on, close your eyes, and point. That’s your next task.

Be realistic about your workload

It’s easy to over-commit yourself when you have ADHD. Your impulsiveness can make you commit to plans you probably should have skipped. Your shame about an especially unproductive period of fatigue can make you feel like you have to overcompensate by doing extra work later. However, preventing a future episode means being unflinchingly honest with yourself about what you can handle. Practice saying no—to your own impulses and to things that others are asking of you.

Make time for mentally soothing activities

Think of a hobby or activity that brings you catharsis or leaves you feeling refreshed afterward. Often, that’s a creative hobby like drawing, playing music, or even journaling. Sometimes, it’s a sport or physical activity. Sometimes, it’s a repetitive craft like knitting or woodworking. Whatever it is, set aside time to do it on a regular basis. Start your day with 15-20 minutes of journaling or free drawing. Commit to spending every Sunday afternoon knitting something for a friend (ideally without TV or other distractions).