Attention deficit/hyperactivity disorder (ADHD) and its prevalence

Authors: Colby Wilson, Aaditya Adlakha, and Dr. Namrata GR Raut

I was referred to MAGIC by my biology teacher after she overheard me discussing my neuroscience project, and then asked me to present it to the class. I was immediately interested in the program as I have always been interested in science, technology, engineering, and mathematics (STEM). Finding a program that specifically catered to this underrepresented demographic was inspiring. MAGIC supported me every step of the way, ensuring I had all that was required for the successful culmination of my project.

As I delved into the process to finalize my project for ten weeks, I along with my mentor chose to work on Attention-deficit/hyperactivity disorder (ADHD). ADHD is the most diagnosed mental health disorder among US children, with 6.1 million children aged 2–17 diagnosed in 2016 (Danielson, M. L. 2016–18). ADHD is typically a lifelong disorder, with 30–60% of children presenting with ADHD as adults, though around half reportedly experience reduced symptoms (Sibley, M. H, 2017). Despite the prevalence of childhood ADHD, there are substantial disparities in diagnosis rates and treatment along racial and gender lines. For example, black Americans are more likely to be diagnosed with ADHD than the general population, but black children are also 66% less likely to receive an ADHD diagnosis and treatment than their white counterparts (Morgan, P. L, 2013) (Cénat, J. M., 2021). Similarly, male children are far more likely to be referred for evaluation, diagnosed, and treated for ADHD than females. This disparity is attributed to differences in how males and females present with ADHD, where males tend toward hyperactive characteristics, and females toward inattention (Skogli, E. W., 2013). Like ADHD, autism spectrum disorder (ASD) is also a lifelong disorder plagued with disparities in diagnosis and treatment along racial lines. ASD occurs in roughly 1.7% of US children (Baio, J, 2018), though ethnic or racial minority children are less likely to receive an appropriate ASD diagnosis compared to white children, and subsequent to a diagnosis, receive less access to treatment and services (Angell, A. M., 2018). These racial and gender disparities make it difficult to correctly characterize and treat any disorder in minority children, and better understand the wide-reaching effects of these disorders, including their effects on sleep patterns.

We tend to define humans as morning or evening people depending on when they prefer to work actively. This is defined by the natural variations in circadian rhythm, called chronotypes. This also plays an important role in the diagnosis of ADHD. Children with evening phenotypes have been found to be associated with substance abuse, poor social skills, sleep insomnia, and ADHD/ASD (Van der Heijden, 2018), which tends to intensify with age.

Interestingly, recent data have demonstrated that ADHD-driven structural differences in the brain persist from adolescent diagnosis into adulthood, even when patients no longer meet diagnostic criteria. Young adults diagnosed with ADHD present persistent caudate structural and functional deficits, which are associated with abnormal working memory function (Roman-Urrestarazu, 2016). Other analyses have demonstrated that ADHD neuroimaging is highly variable in children. Although a meta-analysis demonstrated no consistency in neuroimaging results across ADHD studies, a sub-analysis revealed that male children with ADHD had aberrant activity in the left pallidum/putamen and decreased activity in the left inferior frontal gyrus (Samea, F., 2019). Dysfunction in these regions of the brain is associated with the hyperactivity, disinhibition, impulsivity, and inattentive symptoms of ADHD, those commonly detected in male children with ADHD. These data serve to highlight the growing body of evidence that ADHD is not homogenous in presentation, with significant differences in manifestation and comorbid conditions along gender lines. A study in unmedicated ADHD children examined the intersections of gender and diagnosis and executive function impairment (Samea, F., 2019 & Angell, A. M., 2018). Analysis revealed that ratings of co-existing symptoms better identified ADHD in female children compared to male children. The strongest variable for female ADHD children was self-reported higher levels of anxiety, whereas for male ADHD children it was the parental assessment of rule-breaking. Assessment of executive functioning of male ADHD children by parents was also a good determinant. It is therefore critical that both parents and children assess conditions, particularly when considering sleep patterns and difficulties in children with ADHD.

These disparities along gender lines should also be considered within the context of racial disparities as well. Given the notable disparities along racial lines, further effort must be made to better identify ADHD in children across genders and racial identities. Assessments from both parents, clinicians, and oneself are crucial to an appropriate ADHD diagnosis. Symptom persistence rates varied dramatically (from 1.9% to 61.4%) in adulthood (Cénat, J. M., 2021). Diagnosis should be followed with a tailored treatment plan that considers the specific needs of the child and should include appropriate educational, pharmacological, and therapeutic support for both the child and family members as needed (Wilens, T. E, 2015). This must also include consideration of sleep disruption, and support for these children to best facilitate restful, effective sleep.

These studies have highlighted that a better understanding of ADHD gender and race disparities is crucial to appropriate diagnosis and treatment. Furthermore, the differences between presentations of ADHD in males and females must be considered in all aspects of the child’s life, ranging from therapeutic interventions to the structuring of daily life and sleep-wake patterns.

Once a child is diagnosed with ADHD or ASD, the parents often feel overwhelmed by the treatment options that are available out there. Therefore, CDC recommends that parents work closely with others involved in their child’s life like the therapists, teachers, coaches, and other family members. The treatment type generally includes behavior therapy, including training for parents and medications. Although, medications targeting the sleep cycle should be avoided. The sleep abnormalities can be resolved by inculcating a consistent bedtime routine and healthy sleep hygiene practices like avoiding screen time before bed, keeping the bedroom dark, cool and quiet, and following a set bedtime and wake-up time every day. NAMI HelpLine can be contacted at 1–800–950-NAMI (6264) or info@nami.org if one has any questions about ADHD or needs to find support and resources. Also, a reminder, that ADHD or ASD should not be frowned upon or associated with taboo, like many other neuro-disorders.

I would like to appreciate everyone at MAGIC who helped me to complete this project.

References

1. Danielson, M. L. et al. Prevalence of Parent-Reported ADHD Diagnosis and Associated Treatment Among U.S. Children and Adolescents, 2016. Journal of Clinical Child and Adolescent Psychology 47, 199–212 (2018).

2. Sibley, M. H. et al. Defining ADHD symptom persistence in adulthood: optimizing sensitivity and specificity. Journal of Child Psychology and Psychiatry 58, 655–662 (2017).

3. Morgan, P. L., Staff, J., Hillemeier, M. M., Farkas, G. & Maczuga, S. Racial and Ethnic Disparities in ADHD Diagnosis From Kindergarten to Eighth Grade. Pediatrics 132, 85 (2013).

4. Cénat, J. M. et al. Prevalence and Risk Factors Associated With Attention-Deficit/Hyperactivity Disorder Among US Black Individuals: A Systematic Review and Meta-analysis. JAMA Psychiatry 78, 21–28 (2021).

5. Skogli, E. W., Teicher, M. H., Andersen, P. N., Hovik, K. T. & Øie, M. ADHD in girls and boys — gender differences in co-existing symptoms and executive function measures. BMC Psychiatry 13, 298 (2013).

6. Baio, J. et al. Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2014. MMWR Surveillance Summaries 67, 1 (2018).

7. Angell, A. M., Empey, A. & Zuckerman, K. E. A Review of Diagnosis and Service Disparities Among Children With Autism From Racial and Ethnic Minority Groups in the United States. International Review of Research in Developmental Disabilities 55, 145–180 (2018).

8. Van der Heijden, K. B., Stoffelsen, R. J., Popma, A. & Swaab, H. Sleep, chronotype, and sleep hygiene in children with attention-deficit/hyperactivity disorder, autism spectrum disorder, and controls. European Child & Adolescent Psychiatry 27, 99 (2018).

9. Roman-Urrestarazu, A. et al. Brain structural deficits and working memory fMRI dysfunction in young adults who were diagnosed with ADHD in adolescence. European Child and Adolescent Psychiatry 25, 529–538 (2016).

10. Samea, F. et al. Brain alterations in children/adolescents with ADHD revisited: A neuroimaging meta-analysis of 96 structural and functional studies. Neuroscience & Biobehavioral Reviews 100, 1–8 (2019).

11. Wilens, T. E. & Spencer, T. J. Understanding Attention-Deficit/Hyperactivity Disorder from Childhood to Adulthood. http://dx.doi.org/10.3810/pgm.2010.09.2206 122, 97–109 (2015).