Explanation for the high prevalence of ADHD in the United States
In a recent study, Stephen Hinshaw, a distinguished professor of psychology at the University of California, Berkeley, has shed light on the reasons behind the significant variations in Attention Deficit Hyperactivity Disorder (ADHD) prevalence across countries.
Hinshaw's research suggests that social and cultural pressures to "perform" can falsely inflate rates of ADHD diagnosis, particularly in countries like the U.S. where academic success is highly valued. However, international studies have found a consistent rate of diagnosed ADHD in children and teens (5-8%) in countries with compulsory education.
The prevalence of ADHD varies significantly between countries primarily due to differences in diagnostic practices, cultural perceptions, awareness levels, and methodological factors in studies. Key contributors include diagnostic and screening differences, cultural factors and symptom interpretation, methodological variations in studies, awareness and information dissemination, overlap and misdiagnosis with other conditions, and lack of significant inherent biological prevalence differences.
For instance, countries vary in how widely and rigorously ADHD is screened and diagnosed. Higher screening rates and better health infrastructure in developed regions like Shanghai, China, can yield higher reported prevalence compared to less developed areas where ADHD might be underdiagnosed or unrecognized. Cultural understandings of ADHD symptoms differ, with the translation of ADHD as “Duo Dong Zheng” in China emphasizing hyperactivity, possibly causing caregivers to either over-report based on hyperactivity alone or fail to recognize inattentive and executive function symptoms.
Professor Joel Nigg, co-director of the Center for Mental Health Innovation at Oregon Health & Science University's School of Medicine, suggests that regional differences in relevant risk factors, such as air pollution, ambient lead exposure, poverty, and resource availability for families, may account for within-country regional variation in ADHD diagnosis.
In the U.S., children are more often screened for ADHD by primary care physicians than in some other places in the world. Clinician ideas of how to diagnose ADHD and at what threshold vary widely, leading to marked differences in identification rates within the U.S.
A psychologist specializing in ADHD and other developmental conditions at Syracuse University suggests that medical, social/cultural, and educational factors contribute to higher ADHD prevalence in the U.S. Hinshaw's research with health economist Richard Scheffler found that state-by-state differences in educational policies related to district-wide standardized test scores can lead to precipitous increases in ADHD diagnoses.
In the U.S., an estimated 7 million children (11.4% of all children) have been diagnosed with ADHD. An ADHD diagnosis can lead to the provision of school services, resources, and accommodations, creating an inherent incentive to diagnose the condition. 15.5 million U.S. adults (6% of the adult population) have also been diagnosed with ADHD, half of whom were diagnosed as children.
The U.S. and Israel have rates of diagnosed ADHD well above these international rates, which Hinshaw attributes to extreme levels of academic pressure to succeed. The prevalence of diagnosed ADHD has steadily risen in the U.S. over time, and ADHD rates tend to be lower globally compared to the U.S., but are increasing in some parts of the world.
Hinshaw also notes that there has been a 100-year-long ignoring and discounting of the possibility that girls and women can "have" ADHD, with his lab's work showing that this is a myth and that girls tend to show a less ornery and overt form of ADHD than boys.
The quality of the health care system in the U.S. can affect ADHD diagnosis, as insufficient resources may lead to ADHD becoming the "low hanging fruit" to address. The U.S. is one of only two countries that allows direct-to-consumer advertising of medications, which may contribute to higher diagnosis and medication rates. Treatment guidelines for ADHD vary across countries, with the U.S. encouraging medication as a first line treatment due to its low cost, general efficacy, and limited availability of other options.
In conclusion, differences in diagnostic criteria application, cultural symptom framing, study methods, and healthcare system factors mostly explain cross-country ADHD prevalence variations. These are compounded by varying awareness and interpretation of ADHD symptoms, leading to wide-ranging reported rates despite similar underlying prevalence globally. This emphasizes the importance of standardized diagnostic approaches and culturally sensitive assessment tools to better compare ADHD prevalence internationally.
- The future of health-and-wellness, particularly mental health, could significant benefit from the advancements in technology and science, as shown by the recent study on Attention Deficit Hyperactivity Disorder (ADHD).
- Gizmodo reported on a study that highlights how social and cultural pressures play a role in ADHD diagnosis rates, specifically in countries where academic success is highly valued.
- The research conducted by Stephen Hinshaw suggests that the future of mental health will require a comprehensive understanding of the cultural and methodological factors that influence diagnostic practices.
- Science has consistently found a rate of diagnosed ADHD in children and teens (5-8%) in countries with compulsory education, but the technology-driven healthcare system in the U.S. may contribute to its higher rates compared to other countries.
