October 29, 2024

Updated Analysis of ADHD Prevalence in the United States: 2018-2021

Attention-Deficit/Hyperactivity Disorder (ADHD) remains a prevalent condition among children and adolescents in the United States. A recent analysis based on the National Health Interview Survey (NHIS), conducted by the National Center for Health Statistics at the CDC, provides an updated look at ADHD prevalence from 2018 to 2021. Here’s a closer look at what the data reveals.

How the Survey Works

The NHIS is an annual survey primarily conducted through face-to-face interviews in respondents’ homes. Telephone interviews are used as a substitute in cases where travel is impractical. For each family interviewed, one child aged 3-17 is randomly selected for the survey through a computer program. Over the four years studied (2018-2021), a total of 26,422 households with children or adolescents participated.

Overall ADHD Prevalence and Age-Related Trends

The analysis found that 9.5% of children and adolescents in the United States had been diagnosed with ADHD, based on reports from family members. However, the prevalence varied significantly with age:

  • Ages 3-5: 1.5%
  • Ages 6-11: 9.6%
  • Ages 12-17: 13.4%

The increase in ADHD diagnosis with age underscores the importance of monitoring children’s developmental needs as they progress through school and adolescence.

Gender Differences: Higher Rates Among Males

The survey revealed a notable difference in ADHD prevalence between genders, with 12.4% of males diagnosed compared to 6.6% of females—nearly a two-to-one gap. This aligns with previous research indicating that ADHD is more frequently diagnosed in boys than girls, though awareness of how ADHD presents differently across genders is growing.

Family Income and ADHD Rates

Family income played a significant role in ADHD prevalence, particularly among lower-income groups:

  • Below the poverty line: 12.7%
  • Above the poverty line but less than twice that level: 10.3%
  • Above twice the poverty level: 8.5%

This pattern suggests that socioeconomic factors might influence the diagnosis and management of ADHD, with lower-income families possibly experiencing greater barriers to early diagnosis or consistent treatment.

Regional Differences Across the U.S.

Geographic location also impacted ADHD rates. Prevalence was highest in the South (11.3%), followed by the Midwest (10%), the Northeast (9.1%), and significantly lower in the West (6.9%). These variations could reflect regional differences in healthcare access, diagnostic practices, or cultural attitudes towards ADHD.

Stability Over Time

Despite these variations in demographics, the overall prevalence of ADHD remained relatively stable across the study period from 2018 to 2021, showing no significant changes by year.

What This Means for Families and Healthcare Providers

The findings from this updated analysis provide a clearer picture of ADHD’s prevalence across different demographic groups in the United States. They highlight the need for tailored approaches to diagnosis and care, taking into account factors like age, gender, income, and geographic location. With ADHD being a common condition affecting nearly 1 in 10 children, ongoing research and support for families are crucial to ensure that those with ADHD receive the care and resources they need.

Conclusion: 

This study reinforces the importance of awareness and early intervention, especially for families in underserved regions or those facing economic challenges. As clinicians and educators continue to support children with ADHD, understanding these demographic trends can help in creating more equitable access to diagnosis and treatment.

Qian Li, Yanmei Li, Juan Zheng, Xiaofang Yan, Jitian Huang, Yingxia Xu, Xia Zeng, Tianran Shen, Xiaohui Xing, Qingsong Chen, and Wenhan Yang, “Prevalence and trends of developmental disabilities among US children and adolescents aged 3 to 17 years, 2018–2021,” Scientific Reports (2023) 13: 17254, https://doi.org/10.1038/s41598-023-44472-1

Related posts

Inequities in ADHD diagnosis in the United States

Inequities in ADHD diagnosis in the United States

A transcontinental study team (California, Texas, Florida) used a nationally representative sample – the 2018 National Survey of Children’s Health – to query 26,205 caregivers of youth aged 3 to 17 years old to explore inequities in ADHD diagnosis.  

With increasing accessibility of the internet in the U.S., more than 80% of adults now search for health information online. Recognizing that search engine data could help clarify patterns of inequity, the team also consulted Google Trends.

The team noted at the outset that “[d]ocumenting the true prevalence of ADHD remains challenging in light of problems of overdiagnosis (e.g., following quick screening rather than full evaluation incorporating multi-informant and multi-method data given limited resources) and underdiagnosis (e.g., reflecting inequities in healthcare and education systems).” Underdiagnosis is known to be influenced by lack or inadequacy of health insurance, inadequate public health funding, stigma, sociocultural expectations in some ethnic groups, and structural racism, among other factors.

After controlling for poverty status, highest education in household, child’s sex, and child’s age, the team reported that Black youth were a quarter (22%) less likely to receive ADHD diagnoses than their white peers. Latino/Hispanic youth were a third (32%) less likely and Asian youth three-quarters (73%) less likely to receive ADHD diagnoses than their white peers.

The team also found that state-level online search interest in ADHD was positively associated with ADHD diagnoses, after controlling for race/ethnicity, poverty status, highest education in household, child’s sex, and child’s age. However, the odds ratio was low (1.01), “suggesting the need for additional evaluation.” Furthermore, “There was no interaction between individual-level racial/ethnic background and state-level information-seeking patterns. … the state-level online information-seeking variation did not affect the odds that youth of color would have a current ADHD diagnosis over and above other included characteristics.” 

That could be due in part to the gap in high-speed broadband access between Black and Hispanic in contrast to white populations, but that would not explain the even larger gaps in diagnosis for Asian youth, who tend to come from more prosperous backgrounds.

The team concluded, “Persistent racial/ethnic inequities warrant systematic changes in policy and clinical care that can attend to the needs of underserved communities. The digital divide adds complexity to persistent racial/ethnic and socioeconomic inequities in ADHD diagnosis …”

Variations in Diagnosis

Variations in Diagnosis

A cohort study looked at over five million adults, and over 850,000 children between the ages of five and eleven, who received care at Kaiser Permanente Northern California during the ten-year period from the beginning of 2007 through the end of 2016. At any given time, KPNC serves roughly four million persons. It is representative of the population of the region, except for the highest and lowest income strata.

Among adults rates of ADHD diagnosis rose from 0.43% to 0.96%. Among children the diagnosis rates rose from 2.96% to 3.74%, ending up almost four times as high as for adults.

Non-Hispanic whites had the highest adult rates throughout, increasing from 0.67% in 2007 to 1.42% in 2016. American Indian or Alaska Native (AIAN) had the second highest rates, rising from 0.56% to 1.14%. Blacks and Hispanics had roughly comparable rates of diagnosis, the former rising from 0.22% to 0.69%, the latter from 0.25% to 0.65%. The lowest rates were among Asians (rising from 0.11% to 0.35%) and Native Hawaiian or other Pacific Islanders (increasing from 0.11% to 0.39%).

Odds of diagnosis dropped steeply with age among adults. Relative to 18-24-year-olds, 25-34-year-olds were 1/6th less likely to be diagnosed with ADHD, 35-44-year-olds 1/3rd less likely, 45-54-year-olds less than half as likely, 55-64-year-olds less than a quarter as likely, and those over 65 about a twentieth as likely. This is consistent with other studies reporting and age dependent decline in the diagnosis.

Adults with the highest levels of education were twice as likely to be diagnosed as those with the lowest levels. But variations in median household income had almost no effect. Women were marginally less likely to be diagnosed than men.

ADHD is associated with some other psychiatric disorders. Compared with normally developing adults, and adjusted for confounders, those with ADHD were five times as likely to have an eating disorder, over four times as likely to be diagnosed with bipolar disorder or depression, more than twice as likely to suffer from anxiety, but only slightly more likely to abuse drugs or alcohol.

The authors speculate that rising rates of diagnosis could reflect increasing recognition of ADHD in adults by physicians and other clinicians as well as growing public awareness of ADHD during the decade under study. Turning to the strong differences among ethnicities, they note, Racial/ethnic differences could also reflect differential rates of treatment seeking or access to care. Racial/ethnic background is known to play an important role in opinions on mental health services, health care utilization, and physician preferences. In addition, rates of diagnosis- seeking to obtain stimulant medication for nonmedical use may be more common among white vs nonwhite patients. They conclude, greater consideration must be placed on cultural influences on health care seeking and delivery, along with an increased understanding of the various social, psychological, and biological differences among races/ethnicities as well as culturally sensitive approaches to identify and treat ADHD in the total population.

But the main take home message of this work is that most cases of ADHD in adults are not being diagnosed by clinicians. We know from population studies, worldwide, that about three percent of adults suffer from the disorder. This study found that less than 1 percent are diagnosed by their doctors. Clearly, more education is needed to teach clinicians how to identify, diagnose and treat ADHD in adults.

December 18, 2023

Addressing the challenge of under-diagnosed adult ADHD

Addressing the challenge of under-diagnosed adult ADHD

There is a well-documented gap between the known prevalence of adult ADHD and rates of diagnosis and treatment. In Germany, epidemiological studies of nationally representative community samples have found prevalence rates ranging from 3.1% to 4.7%. Yet, studies of publicly insured individuals aged 18 to 69 years old report rates of diagnosed ADHD between 0.04% and 0.4%. So, even in a country with universal health insurance, more than nine out of ten adults with ADHD go undiagnosed.

Many factors contribute to under-diagnosis: stigma, culturally influenced perceptions, and lack of motivation by those affected. Another crucial factor is the lack of recognition of ADHD symptoms by clinicians.

A research team surveyed 144 psychologists, 32 physicians, and two occupational therapists. Almost three in five participants were psychotherapists, a quarter were neuropsychologists, and one in seven were psychiatrists.

Four out of five clinicians stated they had received only a few hours of ADHD-specific training. One in four stated they had not examined guidelines for diagnosing ADHD. A lack of formal training among the vast majority, and unfamiliarity with current diagnostic guidelines in a significant minority, were surprising findings among clinicians who regularly work with adults with ADHD.

Many clinicians had difficulty identifying core features of adult ADHD as defined by the DSM-5 and International Classification of Diseases, Tenth Revision (ICD-10). Roughly one in five stated that hyperactivity had little relevance to adult ADHD. The only core feature correctly identified by more than half the respondents was having difficulties concentrating. Impairments in social behavior or aggression and memory impairment were not identified as being clearly relevant or irrelevant to adult ADHD.

The authors concluded that these findings appear to indicate some uncertainty or at least a lack of consensus among clinicians about what symptoms are relevant to ADHD in adulthood, and it is likely that this uncertainty contributes to diagnostic inaccuracy.

Most respondents reported using self-report scales of ADHD symptoms and using unstructured interviews. While slightly more than half agreed that collateral reports are important to diagnosis, only about a third reported regularly using them. This is a problem given the limited accuracy of self-reported childhood symptoms for documenting the childhood-onset of the disorder. Semi-structured interviews are also known to improve the accuracy of diagnosis, but are rarely used in clinical practice.

Over half of psychologists and a quarter of physicians reported using cognitive or neuropsychological testing, even though this is at variance with German (and other) guidelines, which specify that such testing is suitable for clarifying strengths and weaknesses, but not for ruling out or confirming a diagnosis of ADHD. The European Consensus Statement also states that cognitive/neuropsychological testing should only be used as a secondary or supplementary assessment tool.

While three out of four clinicians recommended stimulant drug treatment, psychologists tended to be more hesitant to do so. This is likely because German psychologists receive little training in pharmacotherapy, and do not have prescription privileges. Given the demonstrated efficacy of stimulant treatment, this points to a need to better educate psychologists in this regard.

Almost three in four respondents cited a lack of clinician knowledge and experience as a barrier to ADHD diagnosis. Most clinicians also stated they were either uncertain or only somewhat certain of their ability to diagnose ADHD. That suggests that more extensive ADHD-specific training is needed.

A limitation of the survey was the relatively low participation by physicians. It is also likely that the findings are not reflective of practices in ADHD specialty clinics.

The authors concluded, Further training is needed to improve clinicians' understanding of ADHD in adulthood and to align diagnostic practices with guideline recommendations. Whereas discrepancies between respondents regarding the relative importance of peripheral symptoms (e.g., memory problems) were most common, a lack of consensus was found even for core symptoms listed by diagnostic criteria. Particularly among psychologists improved awareness regarding the benefits of stimulant medications is needed to bring their treatment recommendations in line with evidence-based guidelines.

September 22, 2023

Exercise as an ADHD Intervention: What Two Recent Meta-Analyses Tell Us

Exercise has attracted growing attention as an intervention for ADHD. As a potential treatment option for ADHD, it is, of course, highly appealing because it can be low- to no-cost, widely accessible, and free of the side effects that can accompany medication. From previous studies, we know that certain types of exercise may be more effective than others, but do we actually know enough for clinicians to prescribe physical activity as a treatment for ADHD? 

The First Study: Effects on Core ADHD Symptoms 

Despite encouraging findings in individual studies, researchers have lacked clear guidance on which types of exercise work best, at what intensity, and for how long. A meta-analysis by Chen et al. set out to address this by pooling data from 20 randomized controlled trials (RCTs) involving 841 children and adolescents aged 4–18, all of which compared exercise interventions against non-exercising control groups. 

The results were cautiously optimistic. Across standardized symptom scales, exercise produced a small improvement in ADHD symptoms overall. Objective cognitive tests showed a moderate improvement. Emotional and behavioral outcomes, however, showed no significant change. 

To understand what was driving differences between studies, the researchers broke results down by exercise type. Therapeutic and alternative exercises (targeted movements and specific techniques such as those prescribed by physical therapists) were associated with moderate symptom improvements. Mind-body practices (such as yoga or tai chi) showed small-to-moderate gains. Conventional aerobic exercise yielded smaller effects, while skill-based competitive sports showed no measurable benefit. Notably, the variability between individual studies remained high throughout, meaning these categories should be interpreted with some caution. 

Results:

The authors recommend that clinicians and parents consider incorporating therapeutic or alternative exercise sessions twice a week, each lasting 60–90 minutes, as a supplemental strategy alongside existing ADHD treatment. They stop short of calling this definitive, noting that future research should clarify how exercise produces its effects and how it might best be combined with medication or behavioral therapy. 

The Second Study: Effects on Inhibitory Control 

A second meta-analysis, by Zhang et al., zoomed in on a specific and particularly relevant cognitive challenge in ADHD: inhibitory control. Inhibitory control refers to the ability to suppress impulsive responses and tune out irrelevant distractions. This capacity underlies much of the restlessness, interrupting, and difficulty staying on task that characterize the condition. 

This analysis drew on 34 studies with over 1,300 participants spanning all age groups, making it broader in scope than the Chen et al. review. Overall, exercise was associated with a moderate improvement in inhibitory control. When the analysis was restricted to RCTs alone, this finding held up. When studies with a high risk of bias were excluded, however, the effect size dropped to small-to-moderate. 

One notable null result: three studies that used EEG to measure brain activity during inhibitory tasks found no significant effects on the neural signatures most closely tied to this process. This suggests exercise may influence behavior without necessarily changing the underlying brain mechanisms researchers expected, or that current methods aren't yet sensitive enough to detect such changes. 

The dosing question produced some of the more practically useful findings. Single exercise sessions yielded only borderline small improvements. Sustained exercise programs, by contrast, showed moderate improvements, and programs with sessions three times per week produced large gains and had the strongest effect between the two meta-analyses. Exercise intensity and total program duration, perhaps interestingly, were not significant factors. 

Results: 

The authors are measured in their conclusions: exercise shows a real but modest benefit for inhibitory control, and frequency appears to matter more than intensity. They caution against overstating the case for exercise as treatment for ADHD overall, as it did not significantly affect hyperactivity or impulsivity as standalone outcomes, and its neural effects remain unclear. 

The Broader Picture

Ultimately, these two meta-analyses support exercise as a meaningful supplemental intervention for ADHD, particularly for attention and cognitive control, while urging realistic expectations. Neither suggests exercise should replace established treatments. Both are limited by high variability across the underlying studies, and both call for better-designed research to sharpen the guidance available to clinicians and families. 

 

 

 

The Neurocognitive Roots of Boredom in ADHD: a Meta-Analysis

Boredom is more than just feeling restless or under-stimulated. It’s a negative emotional state that arises when activities feel meaningless or dull and, for those with ADHD, this negative emotional state might be markedly more intense. Researchers increasingly view boredom as functional: an internal signal pushing people to seek more rewarding and meaningful experiences. But for some, that signal becomes chronic and overwhelming.

People who are highly prone to boredom face a range of psychological and behavioral consequences, including anxiety, depression, difficulty identifying their own emotions (alexithymia), impulsivity, and physical complaints. These struggles often surface in harmful behaviors: overeating, substance use, compulsive internet use, and gambling.

For people with ADHD, boredom can cross into genuine distress. Many describe it as “torture” or “an itchy coat you can’t scratch”,  language that conveys not mild discomfort but an urgent, almost unbearable need to escape. This makes sense given that ADHD involves core difficulties with attention, arousal regulation, and motivation, all of which make sustained engagement harder and boredom far more likely.

The Study:

A recent meta-analysis of 18 studies involving more than 22,000 participants confirmed a moderately strong and consistent positive association (an overall effect size of r = 0.40) between ADHD and self-reported boredom. All but one study found significant results, and there was no evidence of publication bias.

“While the relationship between ADHD and boredom may seem obvious,” the authors state, “this has paradoxically led to the phenomenon being understudied.”

Despite how significant this connection appears to be, the researchers noted it has attracted surprisingly little scientific attention; a gap they attribute to a widespread assumption that boredom in ADHD is simply a byproduct of inattention or impulsivity, and therefore not worth studying on its own terms. They push back on that view, arguing that boredom may be a more fundamental part of the ADHD experience: a bridge between atypical brain function and the behavioral, emotional, and cognitive difficulties that shape long-term outcomes.

The Take-Away: 

Ultimately, addressing the profound boredom experienced by individuals with ADHD requires a multifaceted approach that goes beyond simply treating inattention. Researchers emphasize the need for rigorous studies to determine if stimulant medications actively reduce this intense boredom by repairing underlying brain mechanisms, rather than just as a side effect of improved focus. Beyond medication, tailored psychological therapies may offer promise; psychoeducation can help individuals reframe boredom as a biological signal rather than a personal failure or character flaw. 

Additionally, another approach suggests that rather than solely focusing on treating the individual, systemic issues must be addressed, such as the effects of low-stimulation environments. For example, prioritizing a better "person-environment fit" through smaller class sizes, flexible academic pacing, and/or offering highly stimulating, novel tasks, schools and workplaces can offer meaningful relief from the chronic distress of ADHD-related boredom. 

May 11, 2026

Early Skull Fusion in Infants Linked to Higher ADHD Risk

A new study from Japan suggests that infants born with craniosynostosis are significantly more likely to be diagnosed with ADHD later in childhood. Craniosynostosis is a condition in which the bony plates of the skull fuse prematurely, leading to increased intracranial pressure. 

The Background:

Craniosynostosis affects roughly one in every 2,000 births. When the skull’s natural seams close prematurely, it can restrict brain growth and increase intracranial pressure, potentially reducing blood flow to the brain. Because the condition is relatively rare, it has been difficult to study at scale until now. 

The Study:

To overcome this, researchers tapped into a large Japanese insurance database compiled by JMDC, Inc., which holds records on around 20 million people, or about 15% of Japan’s population. Drawing on two decades of data, the team tracked over 338,000 mother-child pairs. Children with related genetic syndromes or chromosomal conditions such as Down syndrome were excluded to keep the focus on craniosynostosis itself. 

Of the children studied, around 1,145 had craniosynostosis, and 7,325 were diagnosed with ADHD. After accounting for factors like sex, birth year, maternal age, mental health history, pregnancy infections, and birth complications, children with craniosynostosis were found to have roughly 2.4 times the risk of a subsequent ADHD diagnosis compared to those without it. 

To test whether shared family genetics or home environment might be driving the association rather than the skull condition itself, the researchers conducted a separate analysis among siblings. The elevated risk remained at 2.2 times. The consistency of the finding across both analyses strengthens the case for a genuine biological link. 

The Results:

The results point to raised intracranial pressure and restricted cerebral blood flow as plausible mechanisms, though the study’s observational design means causation cannot be confirmed. Ultimately, these findings highlight the need for proactive, long-term care strategies for those born with craniosynostosis. By establishing a solid link between premature skull fusion and a significantly higher risk of ADHD, the research demonstrates that medical care for this condition should not end once the skull's physical structure is addressed.

The Takeaway:

Pediatricians, neurologists, and parents can use this data to implement early, routine behavioral and developmental screening for these children as they grow. This additional support would ensure that those who do develop ADHD can receive timely interventions, educational aids, and therapies, ultimately improving their long-term developmental outcomes.