ADHD is the most common neurobehavioral disorder affecting children and adolescents. ADHD affects an estimated 3% to 8% of children (aged 5-17 years) and an estimated 4.4% of adults (aged 18 years and older). The National Comorbidity Survey Replication (NCSR) found that in a representative sample of children ages 8 to 15, 8.7% met DSM-IV criteria for ADHD. Of these, although 47.9% had a prior ADHD diagnosis, only 32% had received medication for ADHD for most of the preceding 12 months. (Froehlich 2007) Thus, there is empirical evidence that ADHD is actually underrecognized and undertreated, not overdiagnosed.
Another strong argument against the many opponents’ hypotheses of ADHD being a result of “bad parenting” or “poor diet” is ADHD’s strong familial connection and heritability. In a study of 457 first-degree relatives of clinically referred children and adolescents with ADHD, parents of children and adolescents diagnosed with ADHD had a 29% chance of having ADHD and siblings of children and adolescents diagnosed with ADHD had a 21% chance of having ADHD. (Biederman 2006) In a study of 31 clinically referred adults with ADHD who had children, 57% of children were reported to have ADHD when 1 of their parents was diagnosed with the condition. (Biederman 2005) In fact, many adults recognize ADHD in themselves only after their child has been diagnosed. The heritability of ADHD implies that it is not a condition that is simply being overdiagnosed.
The reason that pediatricians, primary care providers, and psychiatrists look for ADHD in children who present to them with either hyperactivity or inattention more often then they ever have is twofold. The first is the social impact of the disease. Over its course, ADHD causes impairment in multiple facets of a patient’s life, hindering success in school and at work and interfering with the establishment and maintenance of relationships with family and peers. Compared with a control population, people with ADHD are more likely to drop out of high school or college, lose jobs, get divorced, use recreational drugs, have traffic accidents, and be arrested (Biederman 2006). ADHD frequently persists into adulthood, often due to its unrecognizing and childhood, causing substantial impairment in school, work, family, and social settings. Estimates of the societal cost of ADHD range into the tens of billions of dollars. The second reason doctors assess patients for ADHD is the advent of improved diagnostic screening tools. However, despite the impact and the toold, ADHD remains underrecognized and undertreated.
Unlike other psychiatric conditions, ADHD has a specific pathology what can be observed on a functional MRI. Although very few patients diagnosed with ADHD undergo fMRI testing, enough studies have been conducted using the technology to accurately develop screening tools that apply to a larger population. Neurobiological studies of ADHD have implicated the dysregulation of noradrenergic and dopaminergic systems in the brain stem, striatum, cerebellum, and prefrontal cortex. The mechanisms of action of ADHD medications in these regions can give further insight into the pathophysiology of ADHD. Structural and functional abnormalities have been observed in attentional networks of patients with ADHD including: smaller overall cerebral volume and smaller dACC, cortical thinning, dysfunction of fronto-subcortical pathways, and reduced activation of prefrontal cortex and ACC. Increasingly, evidence from neurobiological, neuroimaging, and neuropsychological studies, family and genetic research, and biochemical data on the mechanisms of action of ADHD medications has begun to converge. These studies are providing insight into the pathophysiology of ADHD and are clarifying the roles of neurotransmitters in ADHD and its treatment. Again, the argument can be made that if there is an underlying brain dysfunction then an ADHD diagnosis is an accurate assessment.
Given the defined pathology, heritability and societal impact of ADHD, combined with the significant number of adults who are just now being diagnosed with the disease after years of suffering, it can be stated that ADHD is not over diagnosed in children.
Biederman J, Petty C, Fried R, et al. Impact of psychometrically defined deficits of executive functioning in adults with attention deficit hyperactivity disorder. Am J Psychiatry. 2006;163(10):1730-1738.
Biederman J, Faraone SV. Attention-deficit hyperactivity disorder. Lancet. 2005;366(9481):237-248.
Froehlich TE, Lanphear BP, Epstein JN, Barbaresi WJ, Katusic SK, Kahn RS. Prevalence, recognition, and treatment of attention-deficit/hyperactivity disorder in a national sample of US children. Arch Pediatr Adolesc Med. 2007;161(9):857-864.
Humensky J, Ireys HT, Wickstrom S, Rheault P. Mental health services for children with special health care needs in commercial managed care, 1999-2001. Report submitted to US Department of Health and Human Services, Health Resources and Services Administration, Maternal and Child Health Bureau. February 2004. http://www.mathematica-mpr.com/publications/PDFs/menhlthchil.pdf.
Kessler RC, Adler L, Barkley R, et al. The prevalence and correlates of adult ADHD in the United States: results from the National Comorbidity Survey Replication. Am J Psychiatry. 2006;163:716-723.
Upadhyaya HP. Substance use disorders in children and adolescents with attention-deficit/hyperactivity disorder: implications for treatment and the role of the primary care physician. Prim Care Companion J Clin Psychiatry. 2008;10(3):211-221.