Attention deficit hyperactivity disorder (ADHD) can cause symptoms that people associate with brain fog, including difficulty thinking clearly, inability to concentrate, and issues with memory.

Brain fog can be a symptom of numerous conditions, including dementia, migraine, and certain mood disorders. ADHD and brain fog may overlap for various reasons, including sleep disruption, inflammation, and the side effects of medication.

Although brain fog is not a medical term that doctors recognize as an official diagnosis, it refers to a feeling of cognitive sluggishness.

This article looks at what brain fog is, whether ADHD can cause it, and what it feels like. It explains the treatment and prevention of brain fog for people with ADHD and when to contact a doctor.

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Brain fog” is a general term that refers to cognitive dysfunction and sluggishness that affect a person’s memory, mental clarity, and ability to focus.

Brain fog is not an official medical term and has no diagnostic criteria. Rather, it encompasses a range of cognitive symptoms that describe a decline in thinking, memory, and concentration. People associate it with various health conditions.

The term has gained attention since the onset of the COVID-19 pandemic, as many people experienced a feeling of brain fog as a symptom of the virus.

Symptoms of brain fog may include:

Several symptoms of ADHD overlap with those of brain fog.

A person with ADHD may experience symptoms of hyperactivity, inattention, or both. Symptoms of the inattentive type of ADHD resemble symptoms of brain fog. Overlapping symptoms may include:

Besides sharing symptoms, ADHD may also contribute indirectly to brain fog. This may be due to inflammation, sleep disruption, and ADHD medication side effects.


Researchers believe there is a connection between neuroinflammation and brain fog. Neuroinflammation is inflammation that occurs in the brain or spinal cord.

Proteins called cytokines play an important role in these and other inflammatory responses in the body.

According to a 2017 systematic review, high levels of cytokines may affect the ability to think and can lead to symptoms that people associate with brain fog, such as:

  • slower reaction times
  • reduced ability to focus or pay attention
  • problems with working memory

The review authors suggest that people with ADHD may have higher levels of cytokines in their bodies than those without the condition. This could indicate higher levels of inflammation, which may lead to brain fog.

More research is necessary to understand whether there is a link between inflammation and brain fog in people with ADHD.

Sleep disruption

Researchers in a 2018 review suggest that 25–50% of people with ADHD have trouble sleeping and can experience sleep disorders such as insomnia, narcolepsy, and restless leg syndrome.

According to the review, people with ADHD who have sleep disturbances may be more likely to experience certain symptoms that affect cognitive ability.

People also associate many of these symptoms with brain fog. Symptoms of sleep disturbance in people with ADHD can include:

  • difficulty focusing and paying attention
  • difficulty completing tasks, such as schoolwork
  • daytime or excessive sleepiness
  • problems processing information
  • difficulty with thinking

ADHD medication

In a 2018 study, some people reported that taking stimulant medication for ADHD, such as dextroamphetamine (Dexedrine) or methylphenidate (Ritalin), led to brain fog-like symptoms, such as feeling:

  • lifeless
  • zombie-like
  • zoned out
  • drugged

Feeling “zombie-like” may indicate that the dosage of a person’s ADHD stimulant medication is too high and requires adjustment.

Stimulant medications can also cause sleep disturbances, which may contribute to brain fog.

Nonstimulant ADHD medications, such as guanfacine (Intuniv), may also cause brain fog symptoms such as tiredness and fatigue.

Brain fog refers to a decline in cognitive abilities and can make a person feel confused, forgetful, and mentally sluggish.

People with brain fog may find it difficult to concentrate and can experience a decline in mental clarity. They may feel as if their thinking is dull and requires more effort than usual. Brain fog may also cause a person to feel unusually tired.

A person with ADHD may be able to relieve brain fog by treating their ADHD symptoms and addressing complications of the condition, such as sleep disturbances.

Treatment can include:

  • stimulant medications:
    • amphetamine/dextroamphetamine (Adderall)
    • methylphenidate (Ritalin)
    • lisdexamfetamine (Vyvanse)
    • dexamphetamine (Dexedrine)
  • nonstimulant medications:

If a person experiences brain fog as a result of taking stimulant medication, they may consider discussing altering the dosage or type with their doctor. A doctor may also suggest taking a nonstimulant medication instead.

Getting enough good quality sleep

A person may be able to improve the quality and quantity of their sleep and reduce brain fog by practicing good sleep hygiene. This can involve implementing habits such as:

  • keeping the sleeping environment relaxing, dark, quiet, and at a comfortable temperature
  • maintaining a consistent sleep schedule
  • avoiding large meals and caffeine before bedtime
  • removing electronic devices such as smartphones, televisions, and computer screens from the bedroom
  • getting enough physical activity during the day

As well as improving sleep quality, healthcare professionals may suggest other lifestyle changes, such as eating a balanced diet and getting regular exercise.

A person with ADHD may not be able to prevent brain fog, as some of the symptoms overlap with symptoms of inattentive ADHD.

There is no cure for ADHD, but a person may be able to relieve and manage symptoms or reduce their severity with appropriate treatment.

Ensuring their ADHD medication is the correct dosage and adopting lifestyle changes that encourage better sleep may also help someone prevent brain fog.

Someone with ADHD who experiences brain fog may wish to contact a doctor in the following situations:

  • They want to discuss adjusting the dosage of their ADHD medication.
  • They experience sudden or significant worsening of brain fog.
  • They have other symptoms that could indicate an underlying medical condition as the cause of brain fog.
  • They do not experience improvements in brain fog symptoms despite ADHD treatment and lifestyle adjustments.

ADHD resources

Visit our dedicated hub for more research-backed information and in-depth resources on ADHD.

Was this helpful?

Brain fog is not an official diagnosis. The term refers to a decline in cognitive function, including performance in memory, thinking, and concentration. Symptoms of brain fog can occur in people with ADHD.

In addition to sharing symptoms with brain fog, ADHD may contribute to the condition indirectly. This can be due to inflammation, sleep disturbances, and side effects of ADHD medication.

Receiving appropriate ADHD treatment, getting enough quality sleep, and making certain lifestyle adjustments may help relieve or prevent brain fog in people with ADHD.