What We Know About ADHD in Female Populations

A new consensus statement updates what is known about ADHD in girls and women, and offers professional advice

Boys are three times as likely as girls to be diagnosed with ADHD, and anywhere from three to sixteen times more likely to be referred for treatment.

An international team of experts recently published a consensus statement addressing this discrepancy and offering guidance to rectify the imbalance and improve diagnosis and care for girls and women with ADHD. Here are some key conclusions.

ADHD symptoms:

-Experts caution that ADHD behaviors typically express themselves differently in boys than in girls.
-That in turn leads to gender-based biases in teachers and parents. In two studies in which teachers were shown vignettes of individuals with typical ADHD behaviors, switching from female to male names and pronouns led to higher rates of referral for support and treatment.


-A major reason for this different expression of ADHD in boys is that they have much higher rates of comorbid externalizing disorders, such as the conduct disorder and oppositional defiant disorder, leading them to break rules and get into fights in school. This no doubt contributes to lower rates of referral for girls.
-On the other hand, females are more likely to have comorbid internalizing disorders, such as emotional problems, anxiety, and depression. These may be interpreted as primary conditions, and the link to ADHD is missed altogether.
-Because ADHD has come to be associated with many externalizing disorders, it is then easy to fail to identify it when it is associated with internalizing disorders such as eating disorders.
-Untreated ADHD in girls can increase the risk of substance use disorders.

Associated vulnerabilities:

Children with ADHD are more likely to be unpopular with their peers and to experience rejection. Whereas boys are more likely to experience that rejection in physical ways, girls are more likely to experience it in social ways and through cyberbullying. That, in turn, contributes to lower self-esteem, which could explain some comorbid internalizing disorders.

Symptoms of hyperactivity/impulsivity, one of the two key components of ADHD, are associated with higher rates of risk-taking behavior:

- Like males with ADHD, females with ADHD have higher injury rates.
-Both males and females with ADHD are more likely to underachieve in school or drop out altogether.
-Overall, adolescents with ADHD become sexually active earlier, have more sexual partners, and are more frequently treated for sexually transmitted diseases than their normally developing peers. That also leads to higher rates of teenage and unplanned pregnancies.
-As with males with ADHD, females with ADHD have higher rates of criminal behavior than normally developing peers. While females with ADHD are still half as likely to be convicted of a crime than males with ADHD, one study showed they nevertheless are eighteen times more likely to be convicted of a crime than normally developing females.

Compensatory or coping behaviors:

- Girls may turn to drink alcohol, smoking cannabis, smoking cigarettes, or vaping nicotine to cope with emotional anguish, social isolation, and rejection.
-Some girls may seek to build social support through high-risk activities such as joining a gang, becoming promiscuous, and engaging in criminal behavior.

Triggers for possible referral

Ages 5-11:

-Bedwetting, nail-biting

Ages 5-16:

-Early sexualized behavior

Ages 5-18:

-Suspensions, expulsions, frequent detentions
-Poor attendance/truancy
-Consistent lateness, poor organization
-Academic difficulties, low academic self-esteem
-Conduct problems, conflicts with parents and peers
-Bullying (usually as victims)
-Regular tobacco and alcohol use
- Obesity and other eating disorders
- Repeated injuries
- Sleep difficulties
- Executive function difficulties
- Extreme emotional meltdowns

Ages 12 and above:

- Relationship problems, anxiety about relationships
- Social rejection, isolation
- Substance abuse, including alcohol
- Risky sexual behavior
- Underage or unwanted pregnancy
- Delinquency or criminal behavior (including shoplifting, vandalism)
- Low self-esteem
- Self-harm, suicidality

Ages 16 and above:

- Dropping out of school
- Losing jobs
- Parenting problems
- Criminality
- Financial difficulties
- Traffic crashes
- Internalizing conditions: depression, anxiety

Ages 18 and above:

- Gambling problems, compulsive shopping
- Personality disorder
- Chronic fatigue syndrome
- Fibromyalgia

The key message is not to disregard females because they do not present with the externalizing behavioral problems, or the disruptive, hard-to-manage boisterous, or loud behaviors typically associated with males with ADHD.


The authors emphasize that "comprehensive assessment should be completed to accurately capture the symptoms of ADHD across multiple settings, their persistence over time, and associated functional impairments. High rates of comorbidity are typically present. The assessment process is typically tripartite, involving the use of rating scales, a clinical interview, and ideally objective information from informants or school reports."

Rating scales: Ideally rely on those that provide female norms, making them more sensitive to female presentation.

Clinical interviews:

-Be mindful of age-appropriate, common-occurring conditions in females with ADHD, including autistic spectrum disorder, tics, mood disorders, anxiety, eating disorders, fibromyalgia, and chronic fatigue syndrome.
- Be alert to signs of self-harming behaviors(especially cutting), which peak in adolescence and early adulthood.
-Given that heritability of ADHD is high, ranging between 70-80% in both children and adults, be mindful that informants who are family members may also have ADHD (possibly undiagnosed) which may affect their judgment of "typical" behavior. The assessor should obtain specific examples of behavior from the informant and use these to make clinically informed judgments, rather than relying upon the informants' perception of what is typical or atypical.



- Recommendations for medication do not differ by sex, except that pharmacological treatment is generally not advised during pregnancy or breastfeeding.
- A systematic review and network meta-analysis recommended methylphenidate for children and adolescents and amphetamines for adults, taking into account both efficacy and safety. Larger confidence intervals about the tolerability and efficacy of bupropion, clonidine, and guanine were reported, indicating less conclusive results about the efficacy and tolerability of these oral medications. The use of medication should be followed up over time to verify if medications are effective and well-tolerated, and to manage the effects of related conditions(e.g. anxiety, depression) if they emerge.


- Cognitive behavioral therapy (CBT) together with psychoeducation (which can be provided to both patients and parent/guardians together or independently) are the best forms of psychological treatment.
- Parents and other guardians of teenage girls need to be shown how to identify deliberate self-harming or risky behavior.
- Adolescent girls may require assistance in addressing risky behavior (sexual risk, substance misuse) and improving self-management. Girls with ADHD are more vulnerable to sexual exploitation and have higher rates of early and unwanted pregnancy.
- Adults are more likely to require interventions to address employment problems, child-rearing, and parenting. Women with ADHD are also more vulnerable to sexual exploitation, including physical and sexual violence.
- Interventions should support attendance and engagement with education to avoid early school-leaving, diminished educational attainment, and associated vulnerabilities. While externalizing conditions have a greater impact on classroom behavior, internalizing conditions affect motivation and thus the ability to benefit from education.

Institutional outreach

- Educational, social care, occupational, and criminal justice system professionals should be trained to improve the detection and referral of ADHD in girls and women.
- Flexible learning systems and support with childcare can help women with ADHD return to education after having a baby.
- Depending on the country of residence, women who disclose their disability to their employer may be entitled to reasonable adjustments to the workplace to accommodate their condition.
- Low to no-cost apps are available to assist persons with ADHD with itineraries, lists, and reminders.
- Career planning should take into account that some occupations may provide a better fit for women with ADHD: "some individuals with ADHD show a preference for more stimulating environments, active, hands-on, or busy and fast-paced jobs."
- Persons with ADHD, both male and female, make up roughly a quarter of the prison population: "Evidence indicates that ADHD treatment is associated with reduced rates of criminality, is tolerated and effective in prison inmates, and improves their quality of life and cognitive function. This has led to speculation that effective identification and treatment of ADHD may help to reduce re-offending."

The authors concluded, "To facilitate identification, it is important to move away from the previously predominating disruptive boy stereotype of ADHD and understand the more subtle and internalized presentation that predominates in girls and women."

March 1, 2022

New Estimates on Worldwide Prevalence of ADHD

Meta-analysis updates estimates of adult ADHD prevalence worldwide

Twenty studies covering a total of 107,282 participants reported the prevalence of persistent adult ADHD and found that the total pooled prevalence was 4.6%.

An international team of researchers conducted a comprehensive search of the peer-reviewed literature to perform a meta-analysis, with three aims:

1) assess the global prevalence of adult ADHD

2) explore possible associated factors

3) estimate the 2020 global population of persons with adult ADHD.

In doing so, they distinguished between studies requiring childhood-onset of ADHD to validate adult ADHD (persistent adult ADHD) and studies that make no such requirement and examine ADHD symptoms in adults regardless of previous childhood diagnosis (symptomatic adult ADHD).

The search yielded forty articles covering thirty countries. Twenty reported prevalence data on symptomatic adult ADHD, 19 on persistent adult ADHD, and one on both. Thirty-five studies were published in the last decade (2010-2019). Thirty-one included both urban and rural populations. Thirty-five had a quality score of six or above (out of ten). Twenty-five had sample sizes greater than a thousand.

Because the prevalence of ADHD is age-dependent, and different countries vary widely in the age structure of their populations, the authors adjusted country results for their structures. This allowed for meaningful global estimates of the prevalence of adult ADHD.

Twenty studies covering a total of 107,282 participants reported the prevalence of persistent adult ADHD. The pooled prevalence was 4.6%. After adjustment for the global population structure, the pooled prevalence was 2.6%, equivalent to roughly 140 million cases globally.

Twenty-one studies covering 50,098 participants reported on the prevalence of symptomatic adult ADHD. The pooled prevalence was 8.8%. After adjustment for the global population structure, the pooled prevalence was 6.7%, equivalent to roughly 366 million cases globally.

For persistent adult ADHD, adjusted prevalence declined steeply from 5% among 18- to 24-year-olds to 0.8% among those 60 and older.

For symptomatic adult ADHD, adjusted prevalence declined less steeply from 9% among 18- to 24-year-olds to 4.5% among that 60 and older.

In each case, subgroup analyses found no significant differences based on sex, urban or rural setting, diagnostic tool, DSM version, or investigation period, although pooled prevalence estimates of persistent adult ADHD from 2010 onward were almost twice the previous pooled prevalence estimates. For symptomatic adult ADHD, however, differences between WHO (World Health Organization) regions were highly significant, although the outliers(Southeast Asia at 25% and Eastern Mediterranean at 16%) were based on small samples(304 and 748 respectively).

In both cases, between-study heterogeneity was very high (over 97%). The authors noted, "the age of interviewed participants in the included studies was not unified, ranging from young adults to the elderly. Given the fact that the prevalence of adult ADHD decreases with advancing age, as revealed in previous investigations and our meta-regression, it is not surprising to observe such a diversity in the reported prevalence, and the considerable heterogeneity across included studies could not be fully ruled out by a priori selected variables, including diagnostic tool, DSM version, sex, setting, investigation period, WHO region, and WB [World Bank] region. The effects of other potential correlates of adult ADHD, such as ethnicity, were not able to be addressed due to the lack of sufficient information."

In both cases, there was also evidence of publication bias. The authors stated, "we did not try to eliminate publication bias in our analyses, because we deemed that an observed prevalence of adult ADHD that substantially differed from previous estimates was likely to have been published."

January 30, 2022

Adult ADHD: Diagnoses Versus Undiagnosed

How do undiagnosed but symptomatic adults compare with those diagnosed with ADHD?

The study team began with a representative sample of 69,972U. S. adults aged 18 years or older who completed the 2012 and 2013 U.S. National Health and Wellness Survey. These adults were invited to complete the Validate Attitudes and Lifestyle Issues in Depression, ADHD, and Troubles with Eating(VALIDATE) study, which included 1) a customized questionnaire designed to collect data on sociodemographic and clinical characteristics and lifestyle, and2) several validated work productivity, daily functioning, self-esteem, and health-related quality of life (HRQoL) questionnaires. Of the 22,937 respondents, 444 had been previously diagnosed with ADHD, and 1,055 reported ADHD-like symptoms but had no previous clinical diagnosis.

There were no significant differences between the two groups in terms of age, education, income, health insurance, and most comorbid disorders. But those who had not been previously diagnosed were significantly more likely to be first-generation Americans (p<.001), nonwhite (p<.001), unemployed (p=.024), or suffer from depression, insomnia, or hypertension.

After matching the two groups for sociodemographic characteristics and comorbid conditions, covariate comparisons were made between 436 respondents diagnosed with ADHD and 867 previously undiagnosed respondents. Among respondents who were employed, diagnosed individuals registered a mean work productivity loss of 29% as opposed to 49% for the previously undiagnosed (p<.001). They also registered a 37% level of activity impairment versus a 53% level among the undiagnosed(p<.001). On the Sheehan Disability Scale, which ranges from 0 (no impairment) to 30 (highly impaired), the diagnosed group had a mean of 10, as opposed to a mean of 15 for the undiagnosed (p<.001). Diagnosed respondents also significantly outperformed undiagnosed ones on the Rosenberg Self-Esteem Scale (19 versus 15, on a scale of 0 to 30, p<.001), and on two quality-of-life scales (p<.001).

Applying a linear regression mixed model to the matched sets, the diagnosed still scored 16 points better than the undiagnosed on the WPA I: GH Productivity Loss scale (p<.001), 14 points better on the WPA I: GH Activity Impairment scale (p<.001), 4.5 points better on the Sheehan Disability Scale(p<.001), almost 4 points on the Rosenberg Self-Esteem Scale (p<.0001), with comparable gains on the two quality-of-life scales (p<.001 and p<.0001).

The authors concluded, This comparison revealed that individuals who had been diagnosed with ADHD were more likely to experience better functioning, HRQoL [health related quality-of-life], and self-esteem than those with symptomatic ADHD. This result appears to be robust, withstanding several levels of increasingly rigorous statistical adjustment. That points to substantial benefits from the treatment that follows a diagnosis of adult ADHD.

September 4, 2021

The Economic Burden of ADHD

The Economic Burden of ADHD

ADHD, especially when untreated, impairs patients and creates difficulties in families.  Although these are the proximal targets of treatment, ADHD also burdens society due, for example, to underemployment and the use of health resources.   A recent study assessed the economic burden using the danish population registries, researchers, which link medical information with employment, education, crime, and social care registers while maintaining confidentiality. They identified 5,269 adults with adult ADHD who had not been diagnosed with ADHD in childhood and, we can assume, were probably not treated for the disorder. They excluded patients with other psychiatric diagnoses, and cases without a same-sex sibling free of any diagnosed psychiatric diagnoses. That left 460 pairs of same-sex siblings, one with an adult with ADHD and the other with no psychiatric diagnosis. They selected the non-ADHD sibling closest in age to the ADHD sibling. Using siblings mitigated the effects of genetics and upbringing between the ADHD group and normally developing controls.

Looking at personal income (combining work income and public transfers), adults with ADHD on average brought home about 12,000 Euros less - almost a third less - than their sibling counterparts. They also paid 40% less tax. Balancing that out, their after-tax income was roughly 7,500 Euros less than their siblings. With the additional personal cost of prescribed medication(prescriptions are relatively inexpensive in Denmark, and co-payments even more so) the net personal cost to adults with ADHD was 7,700 Euros.

The net public costs were considerably greater. That was primarily due to the reduction in taxes paid (about 4,500 Euros) and increase in income replacement transfers (just over 5,500 Euros). The cost of additional crimes committed by adults with ADHD added another 1,000 Euros. Additional primary and secondary health care costs contributed another 1,000 Euros. Subsidies for prescribed medicines added 661 Euros, but that was partly counterbalanced by a reduction of 344 Euros in education costs. There were no significant differences in costs from traffic accidents or adult continuation of foster care. Overall, the net per capita public cost of adults with ADHD was just over12,400 Euros each year.

Combining public and private costs, the per capita economic burden of adult ADHD was just over 20,000 Euros each year.

The study could not evaluate the extent to which ADHD treatment may reduce the economic burden, but given many studies that show treatment for ADHD reduces impairments, we would expect treatment to have a positive impact on the economic burden.  These results are extremely important for policymakers and for those who control the allocation of treatment in healthcare systems.  Although treating ADHD incurs costs, not treating it incurs even greater costs in the long run

August 15, 2021

Bad eating habits in adults with ADHD

Bad eating habits in adults with ADHD

An Israeli team compared eating habits and body mass index(BMI) in adults with and without ADHD. They recruited 60 students from Hebrew University in Jerusalem between 20 and 30 years old. To avoid bias due to particular diets, the authors excluded vegetarians and vegans, as well as persons with chronic diseases that require altered diets, such as diabetes, inflammatory bowel diseases, and chronic kidney disease. Twenty-nine of the participants had been diagnosed with ADHD.
All participants filled out the Food Frequency Questionnaire, a semi-quantitative scale querying about 119 food items. Based on World Health Organization guidelines, it distinguished between "healthy" items (such as vegetables, fruits, whole grains, and minimally processed foods)and "unhealthy" ones (such as cookies, processed meats, and other processed foods). The data obtained from the questionnaires were linked to a nutrient database to estimate daily nutrient intake. BMI was calculated from heights and weights reported by the students.
No significant differences were found between the two groups for servings, calories, fats, carbohydrates, and proteins. Yet, the ratio of healthy to unhealthy portions was significantly higher among controls than among those with ADHD. Those without ADHD consumed about a quarter more servings of healthy food and about a quarter fewer servings of unhealthy food.
On average, BMI levels were about 13 percent higher in participants with ADHD than among those without, meaning they were significantly more likely to be overweight. This finding is consistent with many prior studies.
The authors concluded, "Although participants in both groups consumed similar amounts of servings, calories, and nutrients, students with ADHD reported eating lower amounts of healthy food and higher amounts of unhealthy food. The results suggest that ADHD is not associated with general overeating, but with a biased proportion of unhealthy versus healthy food consumption."
They also recognized limitations to their study. One was a relatively small sample size and the fact that all participants were recruited from a single university. Another is that they did not try to fully evaluate the effects of medication, other than to note the absence of significant differences in food choices between those who used medication regularly and those who used it only occasionally. An unrecognized limitation was the exclusive reliance on self-reporting, both for food consumption, weight, and height.
Despite these limitations, this study is an important first step toward understanding the eating habits of people with ADHD.  It suggests to me that those treating ADHD should promote healthy lifestyles, as that should reduce ADHD's known risks of obesity and adverse medical outcomes.

July 2, 2021

What Are The Barriers To Understanding ADHD in Primary Care?

What are the barriers to understanding ADHD in primary care?

A newly-published systematic review by a British team identified48 qualitative and quantitative studies that explored "ADHD in primary care, including beliefs, understanding, attitudes, and experiences." The studies described primary care experiences in the U.S., Canada, Europe, Australia, Singapore, Iran, Pakistan, Brazil, and South Africa.

More than three out of four studies identified deficits in education about ADHD. Of particular concern was the training of primary care providers (PCPs), most of whom received no specific training on ADHD. In most places, a quarter or less of PCPs received such training. Even when such training was provided, PCPs often rated it as inadequate and said they did not feel they could adequately evaluate children with ADHD.

There was even less training for adult ADHD. A 2009 survey of 194 PCPs in Pakistan found that ADHD was not included at all in medical training there and that most learned from colleagues. Half readily admitted to having no competence, and less than one in five were shown to have adequate knowledge about ADHD. In a 2009 survey of 229South African PCPs, only 7 percent reported adequate training in childhood ADHD, and a scant one percent in adult ADHD.

These problems were by no means limited to fewer developed countries. A 2001 U.K. survey of 150 general practitioners found that only 6percent of them had received formal ADHD training. In a 2002 study of 499Finnish PCPs, only half felt confident in their ability to diagnose ADHD. A2005 survey of 405 Canadian PCPs likewise found that only half reported skill and comfort in diagnosis. In a 2009 survey of 400 U.S. primary care physicians, only 13 percent said they had received adequate training. A 2017 study of Swiss PCPs found that only five of the 75 physicians in the sample expressed competence in diagnosis.

Eight studies explored knowledge of DSM (Diagnostic and Statistical Manual of Mental Disorders) criteria and clinical guidelines among PCPs. Only a quarter of PCPs were using DSM criteria, and only one in five were using published guidelines. In a 1999 survey of 401 pediatricians in the U.S.and Canada, only 38 percent reported using DSM criteria. A 2004 survey of 723U. S. PCPs found only 44 percent used DSM criteria. In a 2006 UK study of 40general practitioners, only 22 percent were aware of ADHD criteria. In the same year, a survey of 235 U.S. physicians found that only 22 percent were familiar with ADHD guidelines, and 70 percent used child behavior in the office to make a diagnosis. More encouragingly, a 2010 U.S. study reported that the use of APA (American Psychological Association) guidelines by PCPs had expanded markedly between1999 and 2005, from one in eight to one in two.

Given these facts, it is unsurprising that many PCPs expressed a lack of confidence in treating ADHD. In a 2003 survey of 143 South African general practitioners, two-thirds thought it was difficult to diagnose ADHD in college students. A 2012 U.S. study of 1,216 PCPs found that roughly a third lacked confidence in diagnosis and treatment. More than a third said they did not know how to manage adult ADHD. In a 2015 survey of 59 physicians and138 nurses in the U.S., half lacked confidence in their ability to recognize ADHD symptoms. This was especially pronounced among the nurses. A 2001 U.K.survey of 150 general practitioners found that nine out of ten wanted further training on drug treatment, and more than one out of ten were unwilling to prescribe due to insufficient knowledge.

Misconceptions about ADHD were widespread. In a survey of380 U.S. PCPs, almost half thought ADHD medications were addictive, one in five thought ADHD was "caused by poor diet," more than one in seven thought "the child does it on purpose," and one in ten thought medications can cure ADHD. Some studies reported that many PCPs believed ADHD was related to the consumption of sugary food and drink. Others reported a gender bias. A 2002 U.S. study of395 PCPs found that when presented with boys and girls with parent-reported problems, they were significantly more likely to diagnose ADHD in boys.

A 2010 Iranian study of 665 PCPs found that 82 percent believed children adopted ADHD behavior patterns as a strategy to avoid obeying rules and doing assignments. One-third believed sugary food and drink contributed to ADHD. Only 6 percent believed it could be a lifelong condition. Half blamed dysfunctional families. The aforementioned large 2012 U.S. study similarly found that almost half of PCPs believed ADHD was caused by absent or bad parenting. More than half of 399 Australian PCPs surveyed in 2002 believed inadequate parenting played a key role. In a 2003 study of 48 general practitioners in Singapore, a quarter blamed sugar for ADHD. A 2014 survey of 57French pediatricians found that a quarter thought ADHD was a foreign construct imported into France, and 15 percent attributed it to bad parenting. In all, ten studies reported a widespread belief that ADHD was due to bad parenting, with ratios varying from over one in seven PCPs to more than half. They were particularly likely to attribute hyperactivity to dysfunctional families and to dismiss parents' views of hyperactivity as a medical problem as a way to deflect attention from inadequate parenting. While a third of the studies reported on stigma, the surprise was that it did not seem to play as big a role as expected. A 2012study in the Netherlands found that 74 physicians and 154 non-medical professionals matched by age, sex, and education showed no differences in the level of stigmatization toward ADHD.

On the other hand, the studies identified significant resource constraints limiting more effective understanding, diagnosis, and treatment. Given the complex nature of ADHD, the time required to gain relevant information, especially in the context of competing demands on the attention of PCPs, was a limiting factor. Many studies identified a need for better assessment tools, especially for adults.

Another major constraint was PCP's uneasiness about medication. Studies found a widespread lack of knowledge about treatment options, and more specifically the pros and cons of medication relative to other options. This often led to an unwillingness to prescribe.

Yet another limitation was the difficulties PCPs had in communicating with mental health specialists. One study found that less than one in six PCPs received communications from psychiatrists. Much of this was ascribed to "system failure": discontinuity of care, no central accountability, limited resources, buck-passing. Many PCPs were unsure who to turn to. Another problem is often faulty interactions between schools, parents, children, and providers. Parents often fail to keep appointments. Schools and parents often are less than cooperative in providing information. In a 2004 survey of 786 U.S. school nurses, less than half reported good levels of communication between schools and physicians. Schools and parents often apply pressure on PCPs to issue a diagnosis. In the U.S. survey of 723 PCPs, more than half reported strong pressure from teachers to diagnose ADHD, and more than two-thirds said they were under pressure to prescribe medication.

The authors noted, "The need for education was the most highly endorsed factor overall, with PCPs reporting a general lack of education on ADHD. This need for education was observed on a worldwide scale; this factor was discussed in over 75% of our studies, in 12 different countries, suggesting that lack of education and inadequate education was the main barrier to the understanding of ADHD in primary care.

"In addition, "time and financial constraints affect the opportunities for PCPs to seek extra training and education but also affect the communication with other professionals such as secondary care workers, teachers, and parents." The authors cautioned that only eleven of the 48 studies were published since 2010. Also, because it was a systematic review and not a meta-analysis, there was no way to evaluate publication bias.

They concluded, "Better training of PCPs on ADHD is, therefore, necessary but to facilitate this, dedicated time and resources towards education needs to be put in place by the service providers and local authorities."

June 16, 2021

Assessing Undertreatment and Misuse of ADHD Medications on Four Continents

Assessing undertreatment and misuse of ADHD medications on four continents

To what extent are ADHD medications insufficiently used to address properly diagnosed ADHD? To what extent are they misused by persons who are either undiagnosed or improperly diagnosed?
In search of answers, an international team of researchers from Brazil, the United Kingdom, and the United States conducted a systematic review of the peer-reviewed literature and a meta-analysis of studies from four continents - South America, North America, Europe, and Australia.

The benchmarks set for proper ADHD diagnosis were any of the following:
·        Criteria established in the Diagnostic and Statistical Manual of Mental Disorders (DSM)or the International Statistical Classification of Diseases and Related Health Problems (ICD), confirmed by validated diagnostic instruments or clinical interviews.
·        Use of validated ADHD symptom scales with pre-specified thresholds.
·        Participants or caregivers affirming ADHD diagnosis by a physician.

Medications reviewed were those recommended by the majority of the international guidelines-both stimulant(methylphenidate, dexmethylphenidate, amphetamines), and non-stimulant (atomoxetine).
The team excluded studies relying on the insurance health system and third-party reimbursement datasets because the focus was on rates of ADHD medication use in the entire population rather than among individuals searching for treatment.
A meta-analysis of18 studies with a total of 3,311 children and adolescents properly diagnosed with ADHD in seven countries on four continents (Canada, United States, Australia, Brazil, Netherlands, England, Venezuela) found an overall pharmacological treatment rate of only 19%. There was considerable variation, with the highest treatment rates in the United States (frequently over 40%) and the lowest treatment rates in Brazil, Venezuela, and Canada (under 10%). There was no sign of publication bias.
A second meta-analysis pooled 14 studies with a total of 29,559 children and adolescents without a proper diagnosis of ADHD in five countries on four continents (United States, Canada, Venezuela, Australia, Netherlands). Roughly 1% were using ADHD medications. Again, there was considerable variation, with the highest rates of medication misuse being reported in the United States and Venezuela (3-7%). Again, there was no sign of publication bias.
The authors cautioned, "it is important to note that even though the data collected constitute the most comprehensive evidence available in the literature and response/completion rates observed are acceptable, it does not constitute a world representative sample." Also, the predominance of samples from prosperous countries "most certainly inflates the treatment rates due to the exclusion of a large proportion of the world population with significant financial, cultural, and health access barriers to ADHD treatment."
They concluded, "Despite these limitations, our meta-analysis provides evidence for substantial undertreatment of children and adolescents affected by ADHD in different countries. This is a relevant public health issue worldwide since ADHD under treatment is associated with known negative outcomes in education, healthcare, and productivity systems. At the same time, we found evidence of overtreatment/misuse in individuals without a formal ADHD diagnosis. This practice might expose individuals to undesirable side effects of medications, increased risk of medication misuse, and unmeasured costs for the health care system."

May 31, 2021

Myths About The Diagnosis of ADHD


Myth: The ADHD diagnosis is very much "in the eye of the beholder."
This is one of many ways in which the ADHD diagnosis has been ridiculed in the popular media. The idea here is that because we cannot diagnose ADHD with an objective brain scan or a blood test, the diagnosis is "subjective" and subject to the whim and fancy of the doctor making the diagnosis.

Fact:  The ADHD diagnosis is reliable and valid.
The usefulness of a diagnosis does not depend on whether it came from a blood test, a brain test, or from talking to a patient. A test is useful if it is reliable, which means that two doctors can agree on who does and does not have the disorder, and if it is valid, which means that the diagnosis predicts something important to the doctor and patient, such as whether the patient will respond to a specific treatment. Many research studies show that doctors usually agree about who does and does not have ADHD. This is because we have very strict rules that one must use to make a diagnosis. Much work over many decades has also shown ADHD to be a valid diagnosis. For details see: Faraone, S. V. (2005). The scientific foundation for understanding attention-deficit/hyperactivity disorder as a valid psychiatric disorder. Eur Child Adolesc Psychiatry, 14, 1-10. The short story is that the diagnosis of ADHD is very useful for predicting what treatments will be effective and what types of problems ADHD patients are likely to experience in the future.

Myth: ADHD is not a medical disorder.  It's just the extreme of normal childhood energy
Mental health professionals use the term "disorder" to describe ADHD, but others argue that what we view as a disorder named ADHD is simply the extreme of normal childhood energy. After all, most healthy children run around and don't always listen to their parents. Doesn't the ADHD child or adult simply have a higher dose of normal behavior?

Fact: Doctors have good reasons to describe ADHD as a disorder
The idea that the extreme of normal behavior cannot be a disorder is naïve. Consider hypertension(high blood pressure). Everyone has blood pressure, but when blood pressure exceeds a certain value, doctors get worried because people with high values are at risk for serious problems, such as heart attacks. Consider depression. Everyone gets sad from time to time, but people who are diagnosed with depression cannot function in normal activities and, in the extreme, are at risk of killing themselves. ADHD is not much different from hypertension or depression. Many people will show some signs of ADHD at some times, but not all have a "disorder." We call ADHD a disorder not only because the patient has many symptoms, but also because that patient is impaired, which means that they cannot carry out normal life activities. For example, the ADHD child cannot attend to homework or the ADHD adult cannot hold a job, despite adequate levels of intelligence. Like hypertension, untreated ADHD can lead to serious problems such as failing in school, accidents, or an inability to maintain friendships. These problems are so severe that the center for Disease Control described ADHD as  "serious public health problem."

Myth: The ADHD diagnosis was developed to justify the use of drugs to subdue the behaviors of children.
This is one of the more bizarre myths about ADHD. The theory here is that to sell more drugs, pharmaceutical companies invented the diagnosis of ADHD to describe normal children who were causing some problems in the past.

Fact: ADHD was discovered by doctors long before ADHD medications were discovered.
People who believe this myth do not know the history of ADHD. In 1798, long before there were any drugs for ADHD, Alexander Crichton, a Scottish doctor, described a "disease of attention," which we would not call ADHD.ADHD symptoms were described by a German doctor, Heinrich Hoffman, in1845 and by a British doctor, George Still, in 1902. Each of these doctors found that inattentive and overactive behaviors could lead to a problem that should be of concern to doctors. If they had had medications to treat ADHD, they probably would have prescribed them to their patients. But a medication for ADHD was not discovered until 1937 and even then, it was discovered by accident. Dr. Charles Bradley from Providence, Rhode Island had been doing brain scanning studies of troubled children in a hospital school. The scans left the children with headaches that Dr. Bradley thought would be relieved by an amphetamine drug. When he gave this drug to the children after the scan, it did not help their headaches. However, the next day, their teachers reported that the children were attending and behaving much better in the classroom. Dr. Bradley had accidentally discovered that amphetamine was very helpful in reducing ADHD symptoms, and amphetamine drugs are commonly used to treat ADHD today. So, as you can see, the diagnosis of ADHD was not "invented" by anyone; it was discovered by doctors long before drugs for ADHD were known.

Myth: Brain scans or computerized tests of brain function can diagnose ADHD.
Someday, this myth may become fact, but for now, and shortly it is a solid myth. You may think this is strange. After all, we know that ADHD is a brain disorder and that neuroimaging studies have documented structural and functional abnormalities in the brains of patients with ADHD. If ADHD is a biological disorder, why don’t we have a biological test for the diagnosis?

Fact:  No brain test has been shown to accurately diagnose ADHD.
ADHD is a biologically based disorder, but there are many biological changes and each of these is so small that they are not useful as diagnostic tests. We also think that there are several biological pathways to ADHD. That means that not all ADHD patients will show the same underlying biological problems. So for now, the only officially approved method of diagnosing ADHD is by asking patients and/or their parents about ADHD symptoms as described in the American Psychological Association's Diagnostic and Statistical Manual

May 13, 2021

Is ADHD a Serious Condition?

Is ADHD a Serious Condition?

In the popular media, ADHD has sometimes been portrayed as a minor condition or not a disorder at all. It is easy to find websites claiming that ADHD is an invention of the medical profession and that the symptoms used to diagnose the disorder are simply normal behaviors that have been "medicalized". These claims are wrong. They miss the main point of any psychiatric diagnostic process, which is to identify people who experience distress or disability due to a set of well-defined symptoms. So, does ADHD cause serious distress and disability? It is a serious psychiatric condition? To illustrate the strong evidence base for the "Yes" answer to that question, my colleagues and I constructed this infographic for our "Primer" about ADHD,http://rdcu.be/gYyV.It describes the many ways in which the symptoms of ADHD impact and impair the lives of children, adolescents, and adults with the disorder. We divided these 'impacts' into four categories: other disorders (both psychiatric and medical), psychological dysfunction, academic and occupational failure, social disability, and risky behaviors. Let's start with other health problems. We know from many studies that have followed ADHD children into adolescence and adulthood that having the disorder puts patients at risk for several psychiatric disorders, addictions, criminality, learning disabilities, and speech/language disorders. ADHD even increases the risk for-psychiatric diseases such as obesity, hypertension, and diabetes. Perhaps most worrisome is that people with ADHD have a small increased risk for premature death. This increased risk is due in part to their having other psychiatric and medical conditions and also to their risky behaviors which, as research documents, lead to accidents and traumatic brain injuries. In the category of psychological dysfunction,' we highlighted emotional dysregulation, which makes ADHD people quick to anger or fail to tame extreme emotions. Other serious psychological issues are low self-esteem and increased thoughts of suicide, which lead to more suicide attempts than for people without ADHD. This increased risk for suicide is small, but it is real. A more prevalent impact of ADHD is the broad category of social disability, which includes marital discord, poor parenting, legal problems, arrests, and incarceration. This typically starts in youth with poor social adjustment and conflict with parents, siblings, and friends. Another common impact of ADHD is on academic and vocational pursuits. ADHD youth are at risk for underachievement in school, repeating grades, and dropping out. As adults, they are more likely to be unemployed or underemployed, which leads to them having lower incomes than expected for their level of school achievement. So, don't believe anyone who claims that ADHD is not a disorder or is only a mild one. To be sure, there is a wide range of impairments among people with ADHD but, in the absence of treatment, they are at risk for adverse outcomes. Fortunately, the medications that treat ADHD have been documented to reduce this risk, which is why they are typically the first-line treatment for most people with ADHD.

May 3, 2021

How to Avoid False Positives and False Negatives when Diagnosing Adult ADHD

How to Avoid False Positives and False Negatives when Diagnosing Adult ADHD?

A recent paper by Margaret Sibley and colleagues addresses a key issue in the diagnosis of adult ADHD. Is it sufficient to only collect data from the patient being diagnosed or are informants useful or, perhaps, essential, for diagnosing ADHD in adults? Dr. Sibley presented a systematic review of twelve studies that prospectively followed ADHD children into adulthood. Each of these studies asked a simple question: What fraction of ADHD youth continued to have ADHD in adulthood. Surprisingly, the estimates of ADHD's persistence ranged from a low of4% to a high of 77%. They found two study features that accounted for much of this wide range. The first was the nature of the informant; did the study rely only on the patient's report, or were other informants consulted. The second was the use of a strict diagnostic threshold of six symptoms. When they limited the analysis to studies that used informants and eliminated the six symptom threshold, the range of estimates was much narrower, 40% to 77%. From studies that computed multiple measures of persistence using different criteria, the authors concluded: "(1) requiring impairment to be present for diagnosis reduced persistence rates; (2) a norm-based symptom threshold led to higher persistence than a strict six-symptom DSM-based symptom count criterion; and (3) informant reports tended to show a higher number of symptoms than self-reports." These data have clear implications for what clinicians can do to avoid false positive and false negative diagnoses when diagnosing adult ADHD. It is reassuring that the self-reports of ADHD patients tend to underestimate the number and severity of ADHD symptoms. This means that your patients are not typically exaggerating their symptoms. Put differently, self-reports will not lead you to over-diagnose adult ADHD. Instead, reliance on self-reports can lead to false-negative diagnoses, i.e., concluding that someone does not have ADHD when, in fact, they do. You can avoid false negatives by doing a thorough assessment, which is facilitated by some tools available at www. ADHD in adults. Command described in CME videos there. If you think a patient might have ADHD but are not certain, it would be helpful to collect data from an informant, i.e., someone who knows the patient well such as a spouse, partner, roommate, or parent. You can collect such data by sending home a rating scale or by having the patient bring an informant to a subsequent visit. Dr. Sibley's paper also shows that you can avoid false-negative diagnoses by using a lower symptom threshold than what is required in the diagnostic manual. The new DSM 5 lowered the symptom threshold for adults from six to five. Can you go lower? Yes, but it is essential to show that these symptoms lead to clear impairments in living. Importantly, this symptom threshold refers to the number of symptoms documented in adulthood, not to the number of symptoms retrospectively reported in childhood. To be diagnosed with ADHD in adulthood, one must document that the patient had at least six impairing symptoms of ADHD before the age of 12.

April 29, 2021

Attention Deficit Hyperactivity Disorder: Fact vs. Fiction

Attention Deficit Hyperactivity Disorder: Fact vs. Fiction

Many myths have been manufactured about attention deficit hyperactivity disorder (ADHD).  Facts that are clear and compelling to most scientists and doctors have been distorted or discarded from popular media discussions of the disorder.   Sometimes, the popular media seems motivated by the maxim "Never let the facts get in the way of a good story."  That's fine for storytellers, but it is not acceptable for serious and useful discussions about ADHD.

Myths about ADHD are easy to find.  These myths have confused patients and parents and undermined the ability of professionals to appropriately treat the disorder.   When patients or parents get the idea that the diagnosis of ADHD is a subjective invention of doctors, or that ADHD medications cause drug abuse, that makes it less likely they will seek treatment and will increase their chances of having adverse outcomes. 

Fortunately, as John Adams famously said of the Boston Massacre, "Facts are stubborn things."  And science is a stubborn enterprise; it does not tolerate shoddy research or opinions not supported by fact.   ADHD scientists have addressed many of the myths about the disorder in the International Consensus Statement on ADHD, a published summary of scientific facts about ADHD endorsed by 75 international ADHD scientists in2002.  The statement describes evidence for the validity of ADHD, the existence of genetic and neurobiological causes for the disorder, and the range and severity of impairments caused by the disorder.   

The Statement makes several key points:

  • The     U.S. Surgeon General, the American Medical Association, the American     Psychiatric Association, the American Academy of Child and Adolescent Psychiatry, the     American Psychological Association, and the American Academy of Pediatrics recognize ADHD as a valid disorder.
  • ADHD     involves a serious deficiency in a set of psychological abilities, and these deficiencies pose serious harm to most individuals possessing the disorder.
  • Many studies show that the psychological deficits in people with ADHD are associated with abnormalities in several specific brain regions.
  • The genetic contribution to ADHD is routinely found to be among the highest for any psychiatric disorder.
  • ADHD     is not a benign disorder. For those it afflicts, it can cause devastating problems.

The facts about ADHD will prevail if you take the time to learn about them. This can be difficult when faced with a media blitz of information and misinformation about the disorder. In future blogs, I'll separate the fact from the fiction by addressing several popular myths about ADHD.

April 25, 2021

Can ADHD be a Deadly Disorder?

Can ADHD be a Deadly Disorder?

In the world of research, it is unusual for a single study to be definitive. A possible exception is a recent report in the highly esteemed Lancet, which concluded that people diagnosed with ADHD were about two times more likely to die early than people without ADHD. The data came from the medical registers of Denmark that include1.92 a million people, of which 32,061 have ADHD. The registers included the times and causes of deaths spanning 32 years.

It is a remarkable resource. We know that people with very severe ADHD are at high risk for substance use disorders and antisocial behaviors. In the Danish study, these disorders also increased the risk for premature death, but the risk was even higher if people with those disorders also had ADHD. ADHD also increased the risk for early death among people without these extra problems. This latter finding points to an ADHD-specific pathway to premature death. What is it?  Well, we know that ADHD people are at risk for injuries, traffic accidents, and traumatic brain injury.  We don't know for certain why, but two symptom clusters of ADHD, inattention, and impulsivity, would be expected to increase the risk for accidents and injuries. For example, adults who are distracted while driving are clearly at risk for accidents. Accidents accounted for most of the early deaths in the Danish study. But the study also found an increase in natural causes of death due to having ADHD. This may be due to the well-replicated association between ADHD and obesity, or the possibility that ADHD symptoms lead to poor health habits.

In the Danish study, the mean age at diagnosis was 12.3, which means that many of the ADHD people in the study were not treated for many years after the onset of symptoms. The risk for early death increased with the age at diagnosis. This suggests that failing to diagnose and treat ADHD early makes the disorder worse and increases the risk for the types of behaviors that lead to premature death. Will these data change public policy or clinician behavior? I hope so. Perhaps the media will stop trivializing ADHD and accept it as a bona fide disorder in need of early identification and treatment.  Policymakers should allocate ADHD people their fair share of healthcare and research resources. For clinicians, early identification and treatment should become the rule rather than the exception.

Talk of premature death will worry parents and patients. That is understandable, but such worries can be alleviated by focusing on two facts: the absolute risk for premature death is low, and this risk can be greatly reduced by seeking and adhering to evidence-based treatments for the disorder.

April 13, 2021

The Goal of ADHD Diagnosis? Safe and Effective Treatment

The Goal of ADHD Diagnosis? Safe and Effective Treatment

The diagnosis of ADHD should only be done by a licensed clinician, and that clinician should have one goal in mind: to plan a safe and effective course of evidence-based treatment. The infographic gives a summary of this diagnostic approach which my colleagues and I prepared for our "Primer" about ADHD,http://rdcu.be/gYyV.  A key point that parents of ADHD youth and adults with ADHD should keep in mind is that there is only one way to diagnose ADHD.An expert clinician must document the criteria for the disorder as specified by either the Diagnostic and Statistical Manual of the American Psychiatric Association, which is now in its fifth edition (DSM-5), or the World Health Organization's International Classification of Diseases (ICD-10). The two sets of criteria are nearly identical. These criteria are most commonly applied by a clinician asking questions of the parent (for children) and/or patient (for adolescents and adults).For children, information from the teacher can be useful. Some clinicians get this information by having the parent ask the teacher to fill out a rating scale. This information can be very useful if it is available.  When diagnosing adults, it is also useful to collect information from a significant other, which can be a parent for young adults or a spouse for older adults. But when such informants are not available, diagnosing ADHD based on the patient's self-report is valid. As the infographic indicates, any diagnosis of ADHD should also assess for comorbid psychiatric disorders, as these have implications for which ADHD medications will be safe and effective. And because a prior history of cardiovascular disease or seizures frequently contraindicate stimulants. These must also be assessed.

April 9, 2021

The Economic Burden of ADHD

The Economic Burden of ADHD

ADHD , especially when untreated impairs patients and creates difficulties in families. Although these are the proximal targets of treatment, ADHD also burdens society due, for example, to underemployment and use of health resources.   A recent study assessed economic burden using the Danish population registries, researchers, which link medical information with employment, education, crime, and social care registers while maintaining confidentiality. They identified 5,269 adults with adult ADHD who had not been diagnosed with ADHD in childhood and, we can assume, were probably not treated for the disorder. They excluded patients with other psychiatric diagnoses, and cases without a same sex sibling free of any diagnosed psychiatric diagnoses. That left 460 pairs of same-sex siblings, one with adult ADHD and the other with no psychiatric diagnosis. They selected the non-ADHD sibling closest in age to the ADHD sibling. Using siblings mitigated effects of genetics and upbringing between the ADHD group and normally developing controls.

Looking at personal income (combining work income and public transfers), adults with ADHD on average brought home about 12,000 Euros less – almost a third less – than their sibling counterparts. They also paid 40% less tax. Balancing that out, their after-tax income was roughly 7,500 Euros less than their siblings. With the additional personal cost of prescribed medication (prescriptions are relatively inexpensive in Denmark, and copayments even more so) the net personal cost to adults with ADHD was 7,700 Euros.

The net public costs were considerably greater. That was primarily due to the reduction in taxes paid (about 4,500 Euros) and increase in income replacement transfers (just over 5,500 Euros).The cost of additional crimes committed by adults with ADHD added another 1,000 Euros. Additional primary and secondary health care costs contributed another 1,000 Euros. Subsidies for prescribed medicines added 661 Euros, but that was partly counterbalanced by a reduction of 344 Euros in education costs. There were no significant differences in costs from traffic accidents or adult continuation of foster care. Overall, the net per capita public cost of adults with ADHD was just over 12,400 Euros each year.

Combining public and private costs, the per capita economic burden of adult ADHD was just over 20,000 Euros each year.

The study could not evaluate the extent to which ADHD treatment may reduce economic burden but given many studies that show treatment for ADHD reduces impairments, we would expect treatment to have a positive impact on economic burden. These results are extremely important for policy makers and for those who control the allocation of treatment in health care systems.  Although treating ADHD incurs costs, not treating in incurs even greater costs in the long run

February 24, 2021

ADHD May Be Underdiagnosed Based on Sociodemographics

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

ADHD is underdiagnosed and most cases of ADHD in adults are not being diagnosed by clinicians.

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%).

The 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 an 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.

February 2, 2021