ADHD Symptom Spotlight: Brain Fog

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ADHD Symptom Spotlight is a series that dives deep into a hallmark or overlooked symptom of ADHD each week. This series is written by experts who also share their tips on managing these symptoms based on firsthand experience and research-backed insights.

Managing your ADHD symptoms can be hard even on your best days. On days when you’re tired, not feeling well, or just generally drained, those symptoms can get even worse, creating an experience that’s popularly known as “brain fog.”

What Is Brain Fog?

Sometimes referred to in research as “sluggish cognitive tempo,” brain fog is characterized by the following symptoms:

  • Mental fatigue
  • Forgetfulness
  • An inability to pay attention to what you’re doing or what’s happening around you (not because you’re distracted by something else, but because your brain is struggling to do so)
  • Slow physical movement
  • Difficulty finding words to express yourself
  • Incoherent or jumbled thoughts that you struggle to make sense of
  • Careless (and sometimes strange) mistakes like leaving the stove on when there’s nothing cooking or putting your keys in the freezer.

Brain fog comes and goes, but when it’s there, it can make other symptoms—especially executive dysfunctions like indecision or lack of focus—even worse. Trying to complete a task when you can barely make sense of your thoughts and feel like your brain and body are moving in slow motion is tough.

Sometimes, it can feel like your brain is just inaccessible. Someone will talk to you, but, even though they’re speaking the same language as you, your brain just isn’t absorbing and processing the words. It’s just a collection of sounds. Likewise, when you try to read, the words on the page have no meaning. You reread the same sentence over and over, but it just doesn’t transmit any information to your brain.

What Causes Brain Fog in ADHD?

Brain fog can be a sign of a number of underlying health problems that can affect people, regardless of whether or not they have ADHD. But having ADHD can cause brain fog episodes. In addition, having ADHD can make it harder to maintain the balanced and healthy lifestyle that would protect your brain from experiencing fog.

Dysregulated Dopaminergic System

The dopaminergic system is a part of the central nervous system that controls cognition, executive functions, motivation, and other processes. When that system doesn’t function properly, it can lead to executive dysfunction, slowed cognition, and memory problems.

In short, dopamine dysregulation can cause episodes of brain fog. While the causes of that dysregulation in ADHD are not well understood, a dysfunctional dopaminergic system is very likely a key factor in ADHD.

This is one reason having ADHD could make you more vulnerable to brain fog.

Brain Inflammation

Some studies point to inflammation in the brain as a potential cause of brain fog because an excess of inflammatory molecules can slow or shut down cognitive functions.

One systematic review of studies on the subject found that chronic, low-grade inflammation in the brain, resulting from an overactive or impaired inflammatory response, correlates with the development of ADHD. (However, inflammation itself doesn't cause ADHD.)

So, if people with ADHD are likely to have chronic inflammation, anything that triggers even more inflammation can make your ADHD symptoms worse to the point that you experience brain fog. Triggers include:

  • Infections (viral and bacterial)
  • Allergies
  • Exposure to pollutants or toxins
  • Stress
  • Smoking cigarettes (which also decreases blood flow to the brain, which can also cause brain fog)
  • Drinking alcohol

Lack of Exercise

Physical exercise stimulates blood flow to the brain and increases oxygen levels in the brain—all while helping increase the levels of neurotransmitters and endocannabinoid receptors that can improve cognitive skills like attention, memory, and executive functions.

So not exercising enough can deprive the brain of those important benefits. Over time, that lack of exercise can lead to cognitive decline, making you more vulnerable to brain fog as you age.

Lack of exercise may also increase your risk of having chronic low-grade inflammation. While inflammation spikes immediately after an intense workout, research shows that people who exercise regularly have improved anti-inflammatory responses and lower overall levels of inflammation in the long term.

Iron Deficiency

For people who menstruate and have ADHD, it may be worth asking your healthcare provider to test your iron levels. One 2021 research paper estimated that between 12% and 18% of the otherwise healthy and fit women in the study were iron deficient—a deficiency that can cause brain fog.

If you menstruate and you find that your brain fog typically kicks in (or gets worse) during your period, try getting checked for the possibility of an iron deficiency.

Air Pollution

While the effects of chronic exposure to air pollutants on our lungs and heart have long been known, a growing body of research is now showing that those same pollutants could be causing neurological problems as well.

Exposure to emissions has been linked to decreased attention span, slowed cognitive functions, and other brain fog-like symptoms. With poor ventilation and filtration, those pollutants can build up in higher concentrations indoors, where Americans spend an average of 90% of their time.

How to Fight Brain Fog Right Now

Here are a couple of tips on what you can do in the moment if you’re already dealing with an episode of brain fog:

  • Get your heart rate up with some jumping jacks, jogging in place, or even dancing.
  • Socialize with other people. This can improve your mood and even help your thinking and memory.
  • Engage in an activity that you enjoy. Try listening to music, reading a book, or practicing mindfulness.

How to Prevent Brain Fog Long-Term

Here are a few ADHD-friendly strategies for preventing brain fog by tackling the underlying health problems that tend to trigger it.

Find Ways to Improve Air Quality

To minimize the brain fog symptoms caused by air pollutants, look for ways to improve the air quality where you spend your time. This could be as simple as opening windows to create better airflow. You could also invest in a small HEPA air purifier for your home or work.

Exercise Regularly

Research confirms that physical exercise can meaningfully improve executive function and cognitive performance in people with ADHD. Its role in reducing long-term inflammation levels could also help prevent brain fog.

People with ADHD might find it difficult to stick with an exercise routine, but there are ways you can mix up your workouts so they're more exciting and you don't get bored. For instance, sign up for a dance class or join a casual sports team. Take up hiking or biking as a hobby. Run around the backyard with your dog.

Another strategy is to find ways to build movement into your routine. Take the stairs instead of the elevator. Bike to the store instead of driving. Grab your coffee to go and walk through the park with your friend instead of sitting at the café. Take a leisurely walk through the neighborhood in the morning while you mentally prepare for the day—or after work while you unwind and transition into relaxation mode.

Find activities that are enjoyable (or at least tolerable), so that you’re more likely to look forward to them.

Remember, it can be difficult for anyone with ADHD to make a routine and stick to it; so don't be hard on yourself if you're not able to follow a schedule. It can take some time and patience to find the best way for you to fit exercise into your life.

Add More Iron to Your Diet

While iron supplements can be an easy way to increase iron intake, they can also cause constipation and other unpleasant side effects. So it’s better to increase iron by simply eating more iron-rich foods and only adding a supplement if your doctor advises it.

Some great ways to add more iron to your diet that are also low-effort enough for your ADHD-induced executive dysfunction include:

Low-Effort Iron-Rich Foods

  • Canned chili (with beef and beans)
  • Dried fruits like raisins or apricots
  • Instant oatmeal
  • Make a smoothie with spinach, kale, or other dark leafy greens

It’s easier for your body to absorb the iron found in meat. However, if you’re on a plant-based diet, you can improve the absorption of iron from plant sources by pairing them with foods high in vitamin C. So throw an orange or frozen berries into your smoothie for an iron and vitamin C-packed treat. 

Coping With Brain Fog

Brain fog can be frustrating, and there may not be a "quick fix" for your symptoms. But there are productive coping mechanisms that can help you learn to live with brain fog with less stress. These strategies include:

  • Write it down: If brain fog is interfering with your memory, try keeping lists of what you want to remember. There are even ADHD-friendly planners you can order online (or create yourself) so that you're keeping track of important things.
  • Switch tasks: If you're struggling with brain fog while trying to complete a task, switch to doing something else. Your focus may improve when you stop fixating on a singular task.
  • Take breaks throughout the day: Taking breaks can be a beneficial strategy for making the day more manageable for people with ADHD. Instead of trying to "push through" your brain fog, give yourself a quick rest before proceeding with an activity.
  • Try deep breathing: This can help you feel more present and may even improve attention in people with ADHD. Even if you can't prevent brain fog from happening, you can work on accepting it when it does occur—so you're not creating additional stress.
  • Show yourself compassion: Instead of calling yourself names or getting angry, try to practice some self-care instead. Your brain fog doesn't mean you're incapable of doing things. You are worthy of your own patience as you navigate this symptom of ADHD.
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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rachael Green
Rachael is a New York-based writer and freelance writer for Verywell Mind, where she leverages her decades of personal experience with and research on mental illness—particularly ADHD and depression—to help readers better understand how their mind works and how to manage their mental health.