April 12, 2022

ADHD is underdiagnosed, to varying degrees, among adults of different ethnicities, ages, and education levels in the U.S.

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.

ADHD Diagnosis Rates:

  • Adults: Diagnosis rates rose from 0.43% in 2007 to 0.96% in 2016.
  • Children: Diagnosis rates went up from 2.96% to 3.74%, nearly four times higher than in adults.

Diagnosis Rates by Ethnicity:

  • Non-Hispanic whites had the highest adult diagnosis rates, increasing from 0.67% to 1.42%.
  • American Indian/Alaska Native (AIAN): Rates grew from 0.56% to 1.14%.
  • Black and Hispanic adults had similar rates: Black adults increased from 0.22% to 0.69%, and Hispanic adults rose from 0.25% to 0.65%.
  • Asian adults had the lowest rates (0.11% to 0.35%), followed by Native Hawaiian/Pacific Islanders (0.11% to 0.39%).

ADHD Diagnosis and Age:

The likelihood of being diagnosed with ADHD dropped sharply with age.

(When compared to 18-24-year-olds):

  • 25-34-year-olds were 16% less likely.
  • 35-44-year-olds were 33% less likely.
  • 45-54-year-olds were less than half as likely.
  • 55-64-year-olds were less than a quarter as likely.
  • Adults over 65 were about 5% as likely.

This matches findings from other studies showing that ADHD diagnoses become less common with age.

Other Factors:

  • Adults with higher education levels were twice as likely to be diagnosed as those with less education.
  • Household income had little effect on diagnosis rates.
  • Women were slightly less likely to be diagnosed than men.

ADHD and Comorbidity:

Adults with ADHD were more likely to have other mental health conditions:

  • Eating disorders: 5 times more likely.
  • Bipolar disorder or depression: Over 4 times more likely.
  • Anxiety: More than twice as likely.
  • Substance abuse: Slightly more likely.

Key Findings:
  1. Rising ADHD Diagnosis Rates: The increase in diagnoses may be due to better recognition of ADHD by doctors and greater public awareness during the study period.
  2. Differences by Ethnicity: The differences in diagnosis rates by ethnicity could be related to access to healthcare, cultural attitudes toward mental health, or even attempts to obtain ADHD medications for non-medical reasons, which may be more common among white patients.
Conclusion:

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 notable differences by ethnicity, 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 non-medical 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.”

The study highlights that many cases of adult ADHD go undiagnosed. Research shows about 3% of adults worldwide have ADHD, but this study found that less than 1% are diagnosed by doctors. This points to the need for better training for clinicians to recognize, diagnose, and treat ADHD in adults. It also emphasizes the importance of understanding cultural factors that affect how people seek and receive care.

Winston Chung, MD, MS; Sheng-Fang Jiang, MS; Diana Paksarian, MPH, PhD; Aki Nikolaidis, PhD; F. Xavier Castellanos, MD; Kathleen R. Merikangas, PhD; Michael P. Milham, MD, PhD, “Trends in the Prevalence and Incidence of Attention-Deficit/Hyperactivity Disorder Among Adults and Children of Different Racial and Ethnic Groups,” JAMA Network Open (2019) 2(11): e1914344. DOI:10.1521/adhd.2019.27.4.8.

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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

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 …”

Using Video Analysis and Machine Learning in ADHD Diagnosis

NEWS TUESDAY: Machine Learning and The Possible Future of Diagnosing ADHD

Typically, clinicians rely on both subjective and objective observations, patient interviews and questionnaires, as well as reports from family and (in the case of children) parents and teachers, in order to diagnose ADHD. 

A group of researchers are aiming to find a diagnostic test that is purely objective and utilizes recent technological advancements. The method they developed involves analyzing videos of children in outpatient settings, focusing on their movements. The study included 96 children, half of whom had ADHD and half who did not.

How It Works

  1. Video Recording: Children were recorded during their outpatient visits.
  2. Skeleton Detection: Using a tool called OpenPose, the researchers detected and tracked the children's skeletons (essentially a map of their body's movements) in the videos.
  3. Movement Analysis: The researchers analyzed these movements, looking at 11 different movement features. They specifically focused on the angles of different body parts and how much they moved.
  4. Machine Learning: Six different machine learning models were used to see which movement features could best distinguish between children with ADHD and those without.

Key Findings

  • Movement Differences: Children with ADHD showed significantly more movement in all the features analyzed compared to children without ADHD.
  • Thigh Angle: The angle of the thigh was the most telling feature. On average, children with ADHD had a thigh angle of about 157.89 degrees, while those without ADHD had an angle of 15.37 degrees.
  • High Accuracy: Using thigh angle alone, the model could diagnose ADHD with 91.03% accuracy. It was very sensitive (90.25%) and specific (91.86%), meaning it correctly identified most children with ADHD and correctly recognized most children without it.

This new method could potentially provide a more objective way to diagnose ADHD, reducing the reliance on subjective observations and reports. It can help doctors make more accurate diagnoses, ensuring that those who need help get it and that those who don't aren't misdiagnosed.

May 28, 2024

Meta-analysis Suggests an Adjunct Role for Vitamin D Supplementation for Treating ADHD

Vitamins play important roles in metabolism, immune regulation, and neurodevelopment. Recent studies show that deficiencies in vitamins like D, B6, B12, and folate are common in people with ADHD and ASD (autism spectrum disorder), and are associated with behavioral, cognitive, and brain development issues. 

The Study:

A study team based in China has just performed a systematic search of the peer-reviewed medical literature to perform meta-analyses of clinical trials exploring vitamin interventions in the treatment of ADHD and ASD.  

ADHD trials included participants with an official diagnosis. The primary intervention was vitamin supplements, while other treatments, including medications, remained unchanged or were excluded during the study period. ADHD outcomes included measurable changes in ADHD symptoms using validated rating scales and executive function measures. 

Eligible studies included standard or sham control groups, crossover, parallel, or other clinical trial designs. In crossover studies, only first-phase data were analyzed to prevent carryover effects. 

Ten trials with 852 participants met the standards, but meta-analysis showed no significant results. The outcomes varied widely, suggesting a need to distinguish among vitamins. 

Results:

Of the five trials involving 347 participants that specifically evaluated vitamin D supplementation, results indicated a large effect size improvement in ADHD symptoms and executive function measures. The other five studies did not show any observable improvement. 

Key limitations include: 

  • Vitamin D supplementation studies were not separately assessed. 
  • High heterogeneity persisted in study outcomes, likely due to varying study designs. 
  • Participant numbers were relatively small. 

The team concluded, “This meta-analysis supports the use of vitamin supplementation as a promising adjunctive treatment for ASD and ADHD. Vitamin B showed greater benefits in improving symptoms of ASD, while vitamin D was more effective in managing ADHD-related behaviors. These findings suggest that specific vitamins may target disorder-specific symptoms. Despite limitations such as the lack of trials on other vitamins and limited understanding of underlying mechanisms, vitamin therapy remains a low-cost, accessible option.” 

An important limitation of this work is that the positive results for vitamin D were due to two studies from Iran.  So far, no positive study has emerged from a non-Iranian study.

Interpretation: 

The vitamin D findings are intriguing and could be important if replicated outside of Iran. Since supplementation is already widely recommended to those with limited sunlight exposure, clinicians may want to consider monitoring their patients’ vitamin D intake, especially in the winter months. It should be noted, however, that due to the limitations of this study, the results are by no means conclusive, and vitamin D should not be taken as a stand-alone treatment for ADHD. 

October 10, 2025

Analysis of ADHD Comorbidities and Additional Healthcare Costs

Claims-based real-world data can reveal population-level trends in health among people with neurodevelopmental disorders. This new study examined the prevalence, demographics, and chronic comorbidities of adults and of children and adolescents with ADHD in a large national health plan. It also compared healthcare use and costs between those with and without ADHD. 

A research team in the United States conducted an observational cohort study using claims data from more than 1.9 million adults and nearly 500,000 children and adolescents, comparing individuals diagnosed with ADHD to those without the diagnosis. 

ADHD was diagnosed in 4% of adults and in 5% of children and adolescents. 

Comorbidities By The Numbers: 

Disruptive childhood disorders are behavioral problems marked by ongoing defiance, uncooperativeness, and aggression that affect a child's daily life and relationships. The main types, oppositional defiant disorder (ODD) and conduct disorder (CD), involve persistent anger and argumentativeness in ODD, and more severe actions like aggression, cruelty, and criminal behavior in CD. Without treatment, these common childhood disorders can continue into adulthood and raise the risks of substance use, violence, incarceration, and early death. 

Disruptive childhood disorders were twenty times more frequent among children and adolescents with ADHD than among those without ADHD diagnosis, and fifteen times more frequent among adults with ADHD. 

Bipolar disorder was twelve times more common among children and adolescents with ADHD than those without ADHD, and seven times more common among adults with ADHD. 

Schizophrenia was eleven times more prevalent among children and adolescents with ADHD than those without ADHD, and three-and-a-half times more common among adults with ADHD. 

Anxiety was nine times more frequent among children and adolescents with ADHD than among those without ADHD diagnosis, and more than five times more frequent among adults with ADHD. 

Depression was eight times more common among children and adolescents with ADHD than those without ADHD, and more than five times more common among adults with ADHD. 

Suicidal ideation was eight times more prevalent, and suicide attempt seven times more prevalent, among children and adolescents with ADHD than those without ADHD. Both suicidal ideation and suicide attempt were five times more common among adults with ADHD. 

Gender dysphoria was almost six times more frequent among children and adolescents with ADHD than among those without ADHD diagnosis, and five times more frequent among adults with ADHD.  

Eating disorders were over four times more common among children and adolescents with ADHD than those without ADHD, and five times more common among adults with ADHD. 

Substance-related disorders were over six times more prevalent, and alcohol use disorder was six times more prevalent among children and adolescents with ADHD than those without ADHD, and four and three times more prevalent among adults with ADHD. 

Increased Costs of Medical Care:

These comorbidities and ADHD led to higher medical costs. Children and adolescents with ADHD spent $610 more annually on healthcare than those without, while adults with ADHD had $1,684 higher average yearly expenditures than non-ADHD adults. 

The Take-Away:

This large claims-based analysis of a national commercial insurer found ADHD diagnoses in roughly 4% of adults and 5% of children. It documented substantially higher rates of co-occurring behavioral-health conditions and markedly greater healthcare utilization and expenditures among those with ADHD. The authors report increased odds for several co-occurring diagnoses, as well as higher per-member-per-month (PMPM) spending and per-thousand-per-month (PTPM) utilization, largely driven by greater use of behavioral health services. 

Importantly, these results come from cross-sectional, claims data within a commercially insured population: they describe associations, not causal relationships, and may not generalize to uninsured, publicly insured, or otherwise different populations. These findings, therefore, warrant cautious interpretation and highlight the need for longitudinal and more representative studies to clarify drivers of the increased burden and to inform care and policy.

Population Study Finds Strong Association Between Assisted Reproductive Technologies and Offspring ADHD

Taiwanese Nationwide Population Study Finds Strong Association Between Assisted Reproductive Technologies and Offspring ADHD

Background: 

Since the first in vitro fertilization (IVF) in 1978, assisted reproductive technology (ART) has led to over 10 million births worldwide.  

There are four types of embryo transfers, depending on whether they are fresh or frozen, and on their developmental stage. 

Fresh cleavage stage embryos are transferred on day 2 or 3 following fertilization and typically contain four to eight relatively large, undifferentiated cells. Fresh blastocyst embryos are transferred on day 5 or 6 after fertilization. At this point, they have developed over a hundred cells and have differentiated into two types: the inner cell mass, which develops into the fetus, and the outer cell layer, which forms the placenta. 

Globally, more children are now born through assisted reproductive technology using frozen-thawed embryo transfer than fresh embryo transfer.  

Research suggests that ART-conceived offspring may face increased risks of cardiovascular, musculoskeletal, chromosomal, urogenital diseases, and cancers. Might they also be at increased risk for ADHD? 

Study:

Taiwan’s single-payer health insurance covers over 99% of people and records all their healthcare activity. Since 1998, it has kept an ART database for all couples registered for IVF treatment. 

A Taiwanese research team reviewed all records for the five-year period from 2013 through 2017, ultimately analyzing 3,125 live singleton births from fresh cleavage stages, 1,332 from fresh blastocysts, 1,465 from frozen cleavage stages, and 4,708 from frozen blastocysts, alongside 878,643 naturally conceived singleton births. 

The team controlled for the following potential confounders: pregnancy-induced hypertension, chronic hypertension, diabetes mellitus, gestational diabetes mellitus, unhealthy lifestyle, placenta previa, placenta abruption, preterm premature rupture of membrane, and postpartum hemorrhage. 

Results:

With these adjustments, cleavage stage embryo transfers, whether fresh or frozen, were associated with a seven-fold higher rate of ADHD diagnosis in offspring than natural conception. 

Frozen blastocyst embryo transfers were likewise linked to a seven-fold increase in ADHD diagnoses in offspring compared to natural conception. Notably, fresh blastocyst transfers showed a 19-fold increase, likely due to the smaller number of cases in this category. 

The team concluded, “Compared to natural conception, ART is associated with higher risks, particularly for preterm birth, ADHD, and developmental delay.” 

Conclusion: 

This large national cohort suggests that ART-conceived singletons face higher rates of several adverse outcomes, including preterm birth, ADHD, and developmental delay. Clinicians and prospective parents should therefore weigh these potential associations when counseling and planning care, prioritize optimized ART protocols and perinatal management, and ensure early developmental surveillance for ART-conceived children so concerns can be identified and addressed promptly.

It is important to note that the findings also point to the likely contribution of underlying parental infertility in these developmental outcomes. Future research should aim to disentangle parental- versus procedure-related risks to clarify absolute risk magnitudes. As always, associations of this time should not be interpreted as causal due to the inability of observational studies to rule out all possible confounding factors.

October 1, 2025