Is Caffeine Safe to Use for ADHD Symptoms?

The Many Effects of Caffeine

Caffeine is a white xanthine alkaloid extracted from several plants. It is bitter in taste and the most popular stimulant.

Caffeine can be found in coffee seeds, tea leaves, guarana berries, kola nuts, and other plant sources. It is found in beverages such as tea and coffee and is also commonly added to soft and energy drinks. This alkaloid is also sold as a drug in different dosage forms.

As a stimulant, caffeine acts on the central nervous system. Its main effects are to reduce fatigue, improve mental focus, and stimulate metabolism.

Caffeine is water-soluble and lipid-soluble. Therefore, it can reach most parts of the body. For example, this dual solubility property allows caffeine to cross the blood-brain barrier into the brain.

In the brain, caffeine interferes with the activities of neurotransmitters. It blocks the effects of adenosine, an inhibitory neurotransmitter while increasing the activities of neurotransmitters such as dopamine, glutamate, serotonin, acetylcholine, epinephrine, and norepinephrine.

Caffeine can block adenosine receptors because its chemical structure is similar to that of adenosine.

While blocking these receptors, caffeine does not activate them but prevents adenosine from doing that.

The brain increases the production of adenosine following prolonged mental activity and in response to decreased blood flow to the brain and low oxygen levels. Therefore, adenosine protects the brain by shutting down some parts of the organ.

This is what happens when the accumulation of adenosine in the brain induces sleep.

Caffeine blocks this sleep-promoting effect of adenosine by occupying the receptors required by the inhibitory neurotransmitter without switching them on.

Outside the brain, caffeine increases the rate of metabolism. It switches the body’s primary stored energy source from glycogen to fat. Increased fat utilization can lead to weight loss.

By promoting the breakdown of fat instead of glycogen stored in the muscles, caffeine also increases athletic endurance. This effect is further enhanced by the ability of the alkaloid to reduce the perception of muscular exertion.

Another biological effect of caffeine that may contribute to weight loss is its diuretic property.

Caffeine prevents the reabsorption of water in the kidney. Therefore, it increases urine volume and the frequency of urination. While this diuretic property may cause dehydration especially in people undertaking high-intensity exercises, most regular caffeine consumers develop a tolerance to this effect.

The liver breaks down caffeine into 3 metabolites: paraxanthine, theobromine, and theophylline.

These caffeine metabolites also have biological effects and their actions are considered as part of caffeine’s effects on the body. For example, paraxanthine helps break down fat to supply fatty acids to drive muscular activities.

Theobromine increases the flow of oxygen and nutrient-rich blood to the brain and muscles. Theophylline relaxes bronchial smooth muscles and increases heart rate.

Studies on Caffeine and ADHD Symptoms

Caffeine is popular among parents with ADHD kids and even adults with ADHD. Although it is a stimulant, some people find that it has a calming effect on hyperactivity and that it also improves mental focus.

In a way, caffeine functions just like the common ADHD drugs such as Ritalin which also contain stimulants such as amphetamine. However, caffeine is a weaker stimulant and most people believe it is safer and better tolerated especially since it is commonly found in beverages and herbal trees.

Although caffeine is usually obtained from natural sources, it is still a drug and a stimulant. Therefore, selling it as a natural remedy is both the truth and a sales pitch.

As the use of caffeine becomes increasingly popular in the off-label treatment of ADHD, there have been some studies done to investigate the efficacy and safety of this alkaloid for the neurobehavioral disorder.

Is It Effective?

In a study published in 2005 in The International Journal of Neuropsychopharmacology, researchers investigated the effectiveness of caffeine on rats induced with an ADHD-like disorder.

The researchers used a group of adult female Wistar rats as control while the test subjects were spontaneously hypertensive rats (SHR). SHR is considered the best genetic model for ADHD in rodents because these rats show all of the classic symptoms of ADHD.

By administering caffeine to the rats before and after training as well as 30 minutes before their sessions in the Morris water maze, the researchers were able to test the effects of caffeine on spatial learning.

The result showed that the SHR group performed lower in spatial learning than the control group.

However, this learning deficit was removed when caffeine was administered before training the SHR group.

This study showed that caffeine can improve attention, mental focus, and spatial learning while reducing impulsivity and hyperactivity in ADHD rats.

But is the same effect seen in humans?

In a 1994 study published in the Journal of the American Academy of Child and Adolescent Psychiatry, a group of researchers investigated the effects of caffeine on learning, anxiety, and performance in normal school-aged children.

In this crossover study, 21 children were given a placebo as well as 2.5 mg/kg and 5 mg/kg of caffeine. The study result showed that caffeine improves attention and performance on motor tasks.

A 2002 study published in the journal, Food and Chemical Toxicology, also agreed with this conclusion. The researchers believed that caffeine produced modest improvements in behavior and is safe and well-tolerated in children.

While caffeine improves learning and performance in normal children, what about ADHD kids?

A 1975 study published in The American Journal of Psychiatry recruited 8 ADHD children. In that double-blind, crossover study, 20 mg per day of methylphenidate was found to be more effective than the 160 mg daily dose of caffeine for improving ADHD symptoms such as hyperactivity and impulsivity.

This study showed that although methylphenidate outperformed caffeine, caffeine was still effective. However, there are flaws in the design of this study. The main criticisms were that its sample size was too small and that there was no placebo to remove bias.

Another study published in 1979 in the Journal of Abnormal Child Psychology recruited 17 ADHD children who were given a placebo, low dose caffeine, or high dose caffeine. They were then tested one hour later.

The study result showed no significant improvement in symptoms between the placebo group and the caffeine groups.

Although this study suggests that caffeine might have no effects on ADHD symptoms, its conclusions carry little weight because its design is flawed. First, the sample size was too small for the results to be taken as conclusive. Secondly, the study duration was too short.

Is it Safe?

Because caffeine is a stimulant, there are concerns that it may not be safe to use it for long-term treatment of ADHD. Fortunately, the safety profile of caffeine is well studied.

Some of the side effects of caffeine may actually worsen some symptoms of ADHD. A 1998 study published in the journal, Experimental and Clinical Psychopharmacology, agrees with this statement especially when caffeine was given in high doses (greater than 3 mg/kg).

This study also echoes the results of other older and newer studies: that caffeine enhances mental focus and performance in normal, healthy children but its benefits are inconsistent in ADHD children.

Some of the side effects of caffeine at high doses include nervousness and jitters. These may worsen ADHD symptoms.

Therefore, while caffeine consumption may not cause physical side effects, it does seem to worsen behavioral and cognitive functions in normal children. A review of 9 past studies done on the subject, and published in the Archive of Pediatric Adolescent Medicine in 1996, agrees with this conclusion.

In Conclusion

Caffeine only produces moderate improvements in mental focus, cognition, and motor performance in children. These modest benefits are not enough to justify placing children on caffeine.

For ADHD children, caffeine is even less effective, and then it can actually worsen ADHD symptoms.

Since it is not meant to treat ADHD, there is no standard, safe dose of caffeine in ADHD therapy. Therefore, it is easy to increase caffeine doses in a bid to get more of the moderate, inconsistent benefits it provides.

This can easily tip over into overdose and cause symptoms of caffeinism which will only compound ADHD symptoms.

Therefore, ADHD sufferers should avoid caffeine. Besides causing jitters and nervousness, caffeine can also trigger high blood pressure, irregular heartbeat, and insomnia. It may also aggravate an underlying medical condition.

Finally, caffeine withdrawal symptoms can also affect young people as much as adults. Therefore, long-term use of caffeine may actually worsen ADHD symptoms even after the stimulant has been withdrawn.