Children and adults with attention-deficit/hyperactivity disorder (ADHD) struggle with attentive and impulsive behaviors and often experience low self-esteem and performance issues in school.¹ As a result, patients and caregivers may have questions about the ways certain substances might alleviate or increase symptom burden.
One such substance is caffeine, a stimulant found in many commonly consumed foods and beverages. A number of recent studies have sought to examine a potential link between caffeine and ADHD, and the results have varied from one to the next. What has research shown about patients with ADHD and their different possible reactions to caffeine consumption?
Positive Reactions to Caffeine
It has been suggested that caffeine can increase dopamine levels in people with ADHD, helping concentration in the process.² It has also been suggested that caffeine, as a vasoconstrictor, can reduce blood flow in areas of the brain that are overactive in ADHD. However, even considering these possibilities, caffeine alone is not as effective without prescription ADHD medications.
Some studies have also found the potential for caffeine to impact ADHD symptoms. A 2022 review published in Frontiers of Neuroscience examined caffeine’s effects on ADHD and whether it could be beneficial as a therapy in tandem with exercise. The investigators concluded that it was worth considering as part of an overall regimen.³ A different 2022 study in Frontiers of Psychiatry suggested that caffeine consumption in patients with ADHD may not correlate with a more severe symptom burden, and as a result was not a substance likely to be used as self-medication.⁴
In 2020, a study in the Journal of Clinical Medicine looked at caffeine in US Army soldiers with ADHD and found that low doses of caffeine were more likely to help with cognition compared to alcohol use, which was more likely to increase symptom severity.⁵
Research into caffeine’s effects on animals has also shown promising results. In an analysis published in Nutrients in 2022, researchers reviewed a number of studies on the effects of caffeine on ADHD variables (attention, impulse behavior, memory, etc.) in animals.⁶ Looking at these studies, which used mice, rats, and zebrafish, the investigators found caffeine treatments increased attention and improved learning and memory without affecting body weight and blood pressure. They concluded from this data that caffeine could be part of a possible treatment for ADHD.
Negative Reactions to Caffeine
The largest negative reaction patients with ADHD have to caffeine is that as a stimulant, certain quantities can cause sleep deprivation and worsen insomnia. This can cause difficulty concentrating, remembering, and sitting still, and can make these symptoms worse in those with ADHD who already experience them.²
These difficulties sleeping become exacerbated when more caffeine is consumed in later parts of the day. A 2020 study in the Journal of Pediatric Psychiatry found that adolescents with ADHD were more likely to consume caffeine in the afternoon and evening than adolescents who did not have ADHD.⁷ This caffeine use led to an increase in self-reported sleep problems.
Too much caffeine can also potentially lead to irritability, anxiety, and a rapid heartbeat. Combining caffeine with amphetamines may also lead to nausea and stomach pains.²
Ultimately, however, what researchers have found consistently is that patients with ADHD are not a monolith and reactions can vary from patient to patient. Different amounts of caffeine can have different effects; some may find that even a little bit of caffeine causes a negative reaction, while others may not have any reaction at all. Patients will need to determine how caffeine affects them individually with the help of their health care professional.
- Attention-deficit/hyperactivity disorder (ADHD) in children. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/adhd/symptoms-causes/syc-20350889. Updated June 25, 2019. Accessed October 25, 2022.
- Barclay R. How does caffeine affect ADHD? Healthline. https://www.healthline.com/health/adhd/caffeine. Updated January 28, 2019. Accessed October 25, 2022.
- Sogard AS, Mickleborough TD. The therapeutic potential of exercise and caffeine on attention-deficit/hyperactivity disorder in athletes. Front Neurosci. 2022 Aug 12;16:978336. doi: 10.3389/fnins.2022.978336. PMID: 36033633; PMCID: PMC9412016.
- Ágoston C, Urbán R, Horváth Z, van den Brink W, Demetrovics Z. Self-medication of ADHD symptoms: Does caffeine have a role? Front Psychiatry. 2022 Feb 3;13:813545. doi: 10.3389/fpsyt.2022.813545. PMID: 35185656; PMCID: PMC8850715.
- 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.
- Vázquez JC, Martin de la Torre O, López Palomé J, Redolar-Ripoll D. Effects of caffeine consumption on attention deficit hyperactivity disorder (ADHD) treatment: A systematic review of animal studies. Nutrients. 2022 Feb 10;14(4):739. doi: 10.3390/nu14040739. PMID: 35215389; PMCID: PMC8875377.
- Cusick CN, Langberg JM, Breaux R, Green CD, Becker SP. Caffeine use and associations with sleep in adolescents with and without ADHD. Journal of Pediatric Psychology. 2020;45(6):643-653. doi:10.1093/jpepsy/jsaa033.