Overdiagnosis of ADHD?
A global snapshot of diagnostic validity, prevalence, and concerns
Among the most commonly diagnosed mental health disorders, attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that affects individuals worldwide and is characterized by developmentally inappropriate levels of inattention, hyperactivity, and/or impulsivity. In the field of child and adolescent mental health, some of the hottest topics of debate are concerns from the general public and lay press as well as from some in the scientific community about the diagnostic validity of ADHD across cultures, the increased prevalence of ADHD, and whether the increase can primarily be explained by overdiagnosis. Several recent publications in Pediatrics  and the International Journal of Epidemiology  provide data to shed some light on the above concerns. Both studies were well-designed and used meta-analysis, a statistical technique for combining the findings from independent studies conducted across countries.
Diagnostic validity of ADHD across cultures
One of the criticisms about ADHD is that the wide variability in prevalence estimates across countries suggests problems with the validity of the diagnosis. In particular, critics cite the higher prevalence of ADHD in Western societies (especially in the US) as evidence that the disorder is manufactured and/or pathologizes normal behaviors of children. Results from the study in the International Journal of Epidemiology  did support variability in prevalence estimates across countries. However, the ADHD estimates for North America were not significantly different than those of Europe, Oceania, South America, Asia, Africa, and the Middle East. The authors concluded that any variability in estimates was primarily accounted for by heterogeneous study methodologies rather than by problems with the validity of the diagnosis. In particular, the authors noted that the studies varied greatly in their sampling techniques, diagnostic criteria, and informants, among other factors. Although further study is needed, these findings do suggest that concerns about the validity of the ADHD diagnosis may be overblown.
Increased prevalence of ADHD across cultures?
Many questions have arisen about the true global prevalence of child and adult ADHD and whether there has been a sharp increase in the rates of diagnosis over the last several decades. Findings from the study published in by in Pediatrics  reported that the worldwide prevalence of ADHD was estimated to be at 7.2% for children and adolescents and at 3.4% for adults. Interestingly, the authors concluded that the estimates of prevalence did not statistically significantly increase over time, even though different diagnostic criteria have been used.
Is ADHD overdiagnosed?
There is a healthy debate about whether ADHD is under- or overdiagnosed. Underdiagnosis of ADHD is problematic because the symptoms of ADHD, when left untreated, can result in many negative psychosocial and academic outcomes over the short- and long-term. Conversely, overdiagnosis of any disorder is a serious concern as it negatively impacts those who do not have significant impairment and who would not be expected to benefit from treatment. There are widespread concerns about overdiagnosis of ADHD; however, most of these worries originated in the US. For example, survey data from the Centers for Disease Control and Prevention , released in 2013, revealed a significant rise (a 41% increase) over the last decade in the overall diagnostic rates of ADHD in children and adolescents living in the US. Results from the study in the International Journal of Epidemiology  did not suggest an increase in the number of children in the community who meet criteria for ADHD when standardized diagnostic procedures were employed. The key to this conclusion is the statement “when standardized diagnostic procedures were employed.” Too often, substandard assessments or evaluations are employed resulting in potentially incorrect, or unnecessary, mental health diagnoses.
Although differing rates of ADHD have been found across studies and across countries, the available data do not support the notion that this is due to problematic validity with the diagnosis or rampant overdiagnosis of the disorder. However, many professionals, media commentators, and the public remain fearful of stimulant abuse, physicians overprescribing medications, limited access to ADHD evaluations and treatment as well as a continued unease with the disorder. Although the studies published in Pediatrics  and the International Journal of Epidemiology  provide some valuable new insights into these issues, there is a clear need for further studies that investigate these concerns.
- Thomas, R., Sanders, S., Doust, J., Beller, E., & Glasziou, P. (2015). Prevalence of attention-deficit/hyperactivity disorder: A systematic review and meta-analysis. Pediatrics, 135, 994–1001.
- Polanczyk, G. V., Willcutt, E. G., Salum, G. A., Kieling, C., & Rohde, L. A. (2014). ADHD prevalence estimates across three decades: An updated systematic review and meta-regression analysis. The International Journal of Epidemiology, 43, 434–442.
- Centers for Disease Control and Prevention. (2013). National survey of children’s health. Retrieved from www.cdc.gov/nchs/slaits/nsch.htm
- Connor, D. F. (2011, August). Problems of overdiagnosis and overprescribing in ADHD. Psychiatric Times. Retrieved from https://www.scribd.com/doc/62822748/Problems-of-Over-Diagnosis-and-Over-Prescribing-in-ADHD