Attention deficit hyperactivity disorder (ADHD) is now one of the most common children’s mental health conditions. It involves symptoms of inattention or impulsivity and hyperactivity that lead to behavioral impairments. Approximately 50 percent of children diagnosed with ADHD continue to show clinically significant symptoms and impairment as adults.

A great deal of research has investigated the possible role of caffeine in ADHD. Caffeine is a psychoactive stimulant drug, which can increase alertness and reduce drowsiness. Coffee, tea, soft drinks and chocolate all contain caffeine and are consumed around the world. Approximately 90 percent of adults in North America consume caffeine daily.

It is widely believed that caffeine boosts attention in normal adults, but research results are unclear. Some studies find better performance on memory tasks; others find that caffeine aids concentration but impairs short-term memory. There is also a general belief that caffeine makes people more anxious and hinders sleep. Caffeine withdrawal may trigger headache, fatigue, irritability and nervousness.

As it is a stimulant, caffeine has been investigated as a potential treatment for attention deficit disorder. Its use as a therapy is not widespread because it was found in research studies to be less efficient than other stimulants. But experts writing in 2008 suggest the doses were too low to have a consistent effect. They say that if caffeine proves useful, it “would represent a qualitative increment over the traditional repeated use of psychostimulants, which can have severe side effects if repeatedly used in children.”

Anecdotal evidence suggests that many individuals are already using caffeine to self-medicate ADHD in themselves or their children. Many sufferers find it has the opposite effect than it does in other people: instead of making them more active and stimulated, it actually has more of a “calm-down” effect, and encourages sleep.

The effectiveness of coffee in calming ADHD children has become a great discussion point on websites and forums. Many adults with ADHD also turn to coffee. In fact, some can’t do without it; caffeine’s stimulating effect helps them focus and stay on task.

A similar outcome has been found in animals. A 2005 study of rats with hyperactivity, impulsivity, poor attention, and deficits in learning and memory found a significant improvement in test results when caffeine was administered to the rats beforehand.

The researchers, from the Federal University of Santa Catarina in Brazil, explain that these rats are “considered to be a suitable genetic model for the study of ADHD, since they display hyperactivity, impulsivity, poorly sustained attention, and deficits in learning and memory processes.”

The rats received a dose of caffeine 30 minutes before training, immediately after training, or 30 minutes before a test session in a water maze. These rats needed significantly more training sessions to learn the maze than ordinary rats, but then performed similarly in the test session 48 hours later.

Pre-training caffeine improved the learning deficit in the “ADHD” rats, but had no effect on the other rats. Caffeine given post-training made no difference to either group. “These results demonstrate a selective learning deficit which can be attenuated by pre-training administration of caffeine,” say the researchers.

Caffeine certainly appears to be beneficial for some adults and children with ADHD. But just because it is easily accessible without a prescription, it is still a drug and this does not guarantee a lack of side effects. Overconsumption can be dangerous, especially when consumed on a regular basis over a long period of time. Consuming sugar alongside caffeine in coffee, tea, cola or chocolate may exacerbate attention deficit disorder symptoms.

What’s more, the effects of caffeine are likely to be more short-lived than those from conventional medication, and may diminish over time, as habitual intake can lead to increased tolerance.

A condition known as caffeinism can be triggered when caffeine is consumed in large amounts over an extended period of time. Caffeinism causes nervousness, irritability, anxiety, tremulousness, muscle twitching, insomnia, headaches and heart palpitations. A high intake over time can also lead to peptic ulcers and other gastrointestinal problems.

Caffeine use for ADHD should always be discussed with a physician and may not preclude the need for other medication or therapy.


Lesk, V. E. and Womble, S. P. Caffeine, priming, and tip of the tongue: evidence for plasticity in the phonological system. Behavioral Neuroscience, Vol. 118, 2004, pp. 453-61.

Cunha, R. A. et al. Potential therapeutic interest of adenosine A2A receptors in psychiatric disorders. Current Pharmaceutical Design, Vol. 14, 2008, pp. 1512-24.

Prediger, R. D. et al. Caffeine improves spatial learning deficits in an animal model of attention deficit hyperactivity disorder (ADHD) – the spontaneously hypertensive rat (SHR). The International Journal of Neuropsychopharmacology, Vol. 8, December 2005, pp. 583-94.