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Caffeine for ADHD: Potential Benefits and Drawbacks

When it comes to ADHD management, medication, therapy, and counseling are the most common approaches, but does caffeine have a role to play as well?

There is no doubt that caffeine is one of the most widely used stimulants in the world. It can be found in coffee, tea, sodas, energy drinks, chocolate, and many other foods. Since the majority of ADHD medications are also categorized as stimulants, it’s curious to know if caffeine has comparable benefits.

How does caffeine influence the brain?

When consuming caffeine, one feels more focused and energized, and fatigue is less noticeable. But why? Discussing the underlying brain mechanisms at play is helpful in understanding the connection between ADHD and caffeine.

Primarily, caffeine works by blocking a brain chemical responsible for the sleep-wake cycle called adenosine.


When adenosine levels are low, such as after a restful night's sleep, a person is alert and full of energy. Throughout the day, adenosine levels gradually rise, and one starts feeling exhausted and sleepy. When caffeine is added to the mix, it finds the adenosine receptors in the brain and binds to them. That renders them inactive and prevents adenosine from binding to them. In this way, caffeine counteracts the effects of the brain pathways that make one sleepy.


Caffeine has an indirect effect on dopamine – a familiar neurotransmitter for ADHDers. When the adenosine receptor is blocked by caffeine, it also influences neighboring receptors, including dopamine, rendering them more sensitive. As a result, the effect of dopamine on the brain becomes greater than it would be if the adenosine receptors weren’t occupied by caffeine. With this, a person will notice enhanced concentration and motivation.

Lastly, caffeine also has the property of constricting blood vessels in the brain. Similarly to ADHD medications, this property allows caffeine to reduce blood flow to any brain areas that may be overly active, which should lead to improved focus.

Can caffeine target symptoms of ADHD?

Given that caffeine involves some of the same mechanisms as ADHD medications, consuming caffeinated beverages and foods should theoretically be helpful for ADHD. It’s also known that many ADHDers drink coffee, soda, and energy drinks religiously, even before getting a formal diagnosis.

In general, caffeine is much weaker than carefully prescribed ADHD medication. “The amount of caffeine you’d need to consume to affect ADHD would probably cause agitation,” stated Larry Silver, clinical professor of psychiatry at Georgetown Medical Center in Washington, DC, to Additude Magazine.

Still, for many adults, 1-2 cups of a caffeinated drink may boost their focus. A handful of studies support this. They found similar benefits of caffeine for adults with ADHD:

  • A 2020 paper that investigated the effects of caffeine in US Army soldiers with ADHD stated caffeine was able to reduce impulsivity and boost working memory and alertness.

  • A 2011 study suggested tea as a potential treatment for ADHD in adults. The authors state: “The caffeine in tea can reduce one’s fatigue, increase people’s self-confidence, motivation, alertness, vigilance, efficiency, concentration, and cognitive performance.”

  • Lastly, research from 2012 found that caffeine improved working memory in middle-aged males, but only in low and moderate doses. Interestingly, high amounts of caffeine had the opposite effect.

However, there are few studies on the topic, and positive effects are seen only in adults and adolescents. Moreover, not all adults with ADHD seem to share the same response to caffeine. Some find caffeinated drinks beneficial, whereas others notice no effect or experience reduced attention, increased irritability, and anxiety.

Combining caffeine with ADHD medications

When caffeine is consumed alongside stimulant medications like Adderall, they strengthen each other. Sometimes, this can be beneficial but also amplify side effects. This is why any prescribing professional should be aware of one’s coffee intake before settling on the dose and type of medication. Many ADHDers also find that the amount of coffee they consume naturally drops to just 1 or 2 cups in the morning after they start ADHD medications.

Are there any drawbacks to caffeine?

Like any compound with a stimulative effect, caffeine can have unpleasant side effects. When the initial impact of caffeine starts diminishing, it can lead to a so-called “coffee crash,” making one feel tired, irritable, and less concentrated. The period between being overstimulated and crashing may be very short for a percentage of ADHDers.

Both caffeine and ADHD medication can lead to sleep problems. Hence, consuming caffeine with or without meds like Ritalin, Adderall, and Vyvance can create or exacerbate existing sleep disturbances or insomnia.

According to the Mayo Clinic, caffeine can lead to overstimulation that manifests itself through such side effects as:

  • Headaches

  • Nervousness

  • Heart palpitations

  • Frequent urination

  • Muscle spasms

  • Nausea.

It's best to avoid caffeine altogether if you:

  1. Are pregnant or breastfeeding

  2. Are a child or adolescent

  3. Have anxiety

  4. Have insomnia or a different sleep disorder

  5. Have recurring headaches

  6. Suffer from a cardiovascular or a heart condition.

How much caffeine is too much?

Drinking too much coffee is not a pleasant experience. Besides the immediate effects, such as a racing heart or nervousness, it’s also not good for the body in the long run. That’s why the Food and Drug Administration (FDA) recommends limiting adults’ caffeine intake to 400 milligrams daily — about 4 cups of brewed coffee or 2 shots of espresso.

While this general guideline is helpful, it’s just that – a guideline. Listen to your own body and determine how much caffeine it can tolerate. Even in small quantities, caffeine may reduce one’s symptoms or complement their medication regimen. The flipside may also be true – if even a cup or two of tea or coffee causes anxiety, insomnia, or other adverse effects, excluding caffeine completely may be extremely helpful.

One last note for ADHDers who take coffee to fall asleep

Paradoxically, some individuals with ADHD drink a cup of coffee before bed. While caffeine may help some people fall asleep, it can still affect one’s sleep quality, rendering it less restful and satisfying. Studies show that caffeine shortens the period of slow-wave sleep. As a result, sleep duration is reduced by approximately 1 hour, even if you consume coffee 6 hours prior to bedtime.

The solution? Have the last sip of coffee or a bite of chocolate 10 hours before heading to bed. It will allow caffeine to leave the body prior to bedtime. While this may not be reasonable for everyone, it’s a point to consider for those who feel exhausted in the morning or have insomnia.

(1080 words)


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  • “Caffeine: How Much Is Too Much?” Mayo Clinic. (March 19, 2022.) Accessed March 10, 2023:

  • Cipollone G, Gehrman P, Manni C, Pallucchini A, Maremmani AGI, Palagini L, Perugi G, Maremmani I. Exploring the Role of Caffeine Use in Adult-ADHD Symptom Severity of US Army Soldiers. J Clin Med. 2020 Nov 23;9(11):3788. doi: 10.3390/jcm9113788. PMID: 33238642; PMCID: PMC7700297.

  • Elissa B. Klaassen, Renate H.M. de Groot, Elisabeth A.T. Evers, Jan Snel, Enno C.I. Veerman, Antoon J.M. Ligtenberg, Jelle Jolles, Dick J. Veltman, The effect of caffeine on working memory load-related brain activation in middle-aged males, Neuropharmacology, Volume 64, 2013, Pages 160-167, ISSN 0028-3908,

  • Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013 Nov 15;9(11):1195-200. doi: 10.5664/jcsm.3170. PMID: 24235903; PMCID: PMC3805807.

  • Ian Clark, Hans Peter Landolt, Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials, Sleep Medicine Reviews, Volume 31, 2017, Pages 70-78, ISSN 1087-0792,

  • Kezhi Liu, Xuemei Liang, Weihong Kuang, Tea consumption maybe an effective active treatment for adult attention deficit hyperactivity disorder (ADHD), Medical Hypotheses, Volume 76, Issue 4, 2011, Pages 461-463, ISSN 0306-9877,

  • “Q&A: What about caffeine for ADHD?” Children and Adults with Attention-Deficit/Hyperactivity Disorder (CHADD). Accessed March 10, 2023:

  • “Spilling the Beans: How Much Caffeine is Too Much?” US Food and Drug Administration (FDA). (Dec. 12, 2018). Accessed March 10, 2023:

  • “The Truth About Caffeine and ADHD.” ADDitude Magazine (February 9, 2023). Accessed March 10, 2023:


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