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  • Writer's picturePre-Collegiate Global Health Review

The Global Misdiagnosis of ADHD and the Devastating Long-Term Effects

Avisha Garg, Heritage High School & Academies of Loudoun, Leesburg, Virginia, USA

One of the most globally prevalent neurobehavioral disorders, attention-deficit hyperactivity disorder (ADHD), affects approximately 6.1 million children in the United States alone (CDC, 2020). It was found that childhood ADHD cases from 2003-2011 increased by 42 percent, resulting in questions about the validity of diagnosed cases (NIH, 2017). Furthermore, when compared to other countries, the United States shows an alarmingly high prevalence of ADHD cases in children.

Figure 1. Global prevalence of childhood ADHD based on retrospective recall in adults aged 18–44 years. Figure developed using data from Fayyad J et al. Atten Defic Hyperact Disord 2017 (ADHD Institute, 2021).

ADHD affects attention levels and hyperactivity in children and adults. Although attributed to a number of factors, one of the most widely known causes of ADHD is a deficit in dopamine, norepinephrine, and serotonin neurotransmitters. Neurotransmitters are chemicals responsible for transmitting messages between neurons. A deficiency in these neurotransmitters could lead to erratic mood changes and attentional issues. To raise levels of dopamine, norepinephrine, and serotonin in the brain, agonist psychoactive drugs are used as ADHD treatment. These drugs include methylphenidates, dextroamphetamines, and a combination of amphetamine and dextroamphetamine prescribed as Ritalin, Dexedrine, and Adderall, respectively (Silver, 2020). To function, these psychoactive drugs occupy and activate dopamine, norepinephrine, and serotonin receptors. Although these psycho-stimulants effectively improve alertness and mood control, the brain of a regular user of these stimulants may not naturally produce these neurotransmitters due to drug influence.

ADHD is one of the most commonly misdiagnosed disorders worldwide. Although the number of children wrongly diagnosed with ADHD is unknown, there is evidence to prove the misdiagnosis. Iceland has a high prevalence of high psychoactive drug use in children, and studies found that the youngest third of a school class would be 50 percent more likely to be prescribed psycho-stimulants for the treatment of ADHD (Newmark, 2015). Similarly, a study conducted in Taiwan found a strong influence of age on ADHD diagnosis prevalence, with results displaying higher cases of ADHD in young children when compared to children older by as little as one month (Chen et al., 2016). These findings show that the diagnosis of ADHD may be excessive for younger children at school due to maturity and neurodevelopmental factors. Additionally, research conducted by Michigan State University found that in the United States, almost 1 million children are misdiagnosed with ADHD due to their young age (Michigan State University, 2010).

The use of psychoactive drugs as treatment for those with misdiagnosed ADHD would significantly harm the user. If levels of dopamine, norepinephrine, and serotonin are normal in the brain, using psycho-stimulants to activate neuronal receptor sites would lower levels of naturally occurring neurotransmitters in the brain, as it would no longer need to produce dopamine, norepinephrine, and serotonin. Because a patient relies on ADHD medication to raise levels of neurotransmitters, if they stop using the drugs at any time, levels would greatly decline. The decrease in these natural neurotransmitter levels results in major consequences and risks of neurodegenerative disease. Research indicated that the use of ADHD medication could increase the risk of early-onset Parkinson’s Disease (PD) due to the disturbance of dopamine levels caused by ADHD drugs (Davio, 2018). PD is partly caused by a decrease in dopamine levels in parts of the brain, and people on unnecessary ADHD medication suffer a natural decrease in dopamine throughout the same neurological areas affected by PD. A depletion in natural serotonin and norepinephrine levels could significantly increase the risk of clinical depression in a user of psychoactive drugs for ADHD, as these neurotransmitters are responsible for arousal and feelings. Addiction and misuse of psycho-stimulants may be promoted if the medications are used by those who do not rely on them to control their behavior or attention. In addition, patients with misdiagnosed ADHD could undergo extreme psychosis while taking psycho-stimulants due to the elevation of already balanced neurotransmitter levels.

Battling the misdiagnosis of ADHD worldwide should become a global health priority; several long-term effects could be avoided if ADHD misdiagnosis was not prevalent across the globe. Not only does the misdiagnosis of ADHD negatively impact those wrongly diagnosed, but it wastes a considerable amount of money and may pose potential for higher future disease and mental illness rates. The misdiagnosis of childhood ADHD in the US causes an average of $410 million USD to go towards unnecessary medication, wasting a large sum of money (Michigan State University, 2010). If more time and closer consideration to factors such as age, gender, and setting are implemented while ADHD is being diagnosed, many people could be protected from a lifetime of natural neurotransmitter depletion. While doctors are very commonly correct about the diagnosis of ADHD, awareness about the high rates of ADHD misdiagnosis should be internationally spread, resulting in more caution while blindly accepting a doctor’s ADHD diagnosis. To ensure the correct diagnosis of ADHD, it should be consistently stressed that ADHD symptoms overlap with a variety of conditions, including young age, bipolar disorder, general anxiety disorder, and excitement.

Although there are multiple findings that suggest global misdiagnosis of ADHD, further studies and research will need to be done to learn more about varying ways that ADHD is misdiagnosed and its wide range of future effects. It has not been determined if ADHD is simply misdiagnosed worldwide, and through proper funding and longitudinal studies, a conclusion and suggested preventative plan can be reached. Seemingly high cases in one part of the world could be due to external factors, and may not occur solely because of misdiagnosed cases. The misdiagnosis of ADHD can burden the lives of millions of families throughout the world and should be focused on, preventing lifelong effects.



ADHD & PD: The Basal Ganglia and Cerebellum Connection. Parkinson's Foundation. (n.d.).

ADHD Epidemiology. ADHD Institute. (2021, March 16).

ADHD Institute. (2021). Global prevalence of childhood Adhd based on retrospective recall in adults aged 18–44 years. . ADHD Epidemiology.

Centers for Disease Control and Prevention. (2020, November 16). Data and Statistics About ADHD. Centers for Disease Control and Prevention.

Chen, M. H., Lan, W. H., Bai, Y. M., Pan, T. L., Chen, T. J., Huang, K. L., Su, T. P., Tsai, S. J., Li, C. T., Lin, W. C., Chang, W. H., & Hsu, J. W. (2016, March 10). Influence of Relative Age on Diagnosis and Treatment of Attention-Deficit Hyperactivity Disorder in Taiwanese Children. DEFINE_ME.

Davio, K. (2020, July 30). New Research Finds Link Between ADHD and Parkinson Disease. AJMC.

Dotinga, R. (2020, November 18). Youngest Kids in Class May Be More Likely to Get ADHD Diagnosis. HealthDay.

Editors, A. D. D., & Larry Silver, M. D. (2021, May 10). The Neuroscience of the ADHD Brain. ADDitude.

National Institutes on Aging, NIH. (2017). Synapse Illustration. NIH Image Gallery.

Newmark, S. (2019, September 19). A True ADHD Epidemic or an Epidemic of Overdiagnosis? Psychiatry Advisor.

Person. (2010, August 17). Nearly 1 million children potentially misdiagnosed with ADHD. MSUToday.

Robinson, L. (2021, April 19). ADHD Medications.

This Is How Adderall Really Affects Your Brain. Doctor Segil Neurologist This Is How Adderall Really Affects Your Brain Comments. (n.d.).


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