Attention-deficit / hyperactivity disorder, commonly known as ADHD, has experienced a dramatic rise in the percentage of children diagnosed since the syndrome was first described in 1902. In 1973, not longer after the development of Ritalin and Adderall, fewer than six percent of American children were diagnosed with ADHD. By 2011 - 2012, that figure nearly doubled, with eleven percent of American children aged four through 17 carrying an ADHD diagnosis; 69 percent of these children are taking drugs to treat their ADHD symptoms.
Recently, both specialist physicians who have been advocates for those suffering from ADHD and investigative journalists have questioned whether the rise in ADHD diagnoses represents a true increase in the percentage of ill children in the United States or a growth in the percentage of parents and family physicians susceptible to aggressive marketing campaigns by the makers of such drugs as Daytrana and Concerta. A New York Times article published near the end of 2013 quotes Dr. Keith Conners, a psychologist at Duke University and an expert in the field of ADHD, as saying, "The numbers make it look like an epidemic. Well, it's not. It's preposterous. This is a concoction to justify the giving out of medication at unprecedented and unjustifiable levels."
It may be true that some portion of ADHD diagnoses are the result of parents' susceptibility to marketing campaigns promising higher grades and better-behaved children. It may also be true that schools are contributing to the rise in ADHD diagnoses by suggesting medication to parents of young boys who display activity levels considered typical a few generations ago. However, it may also be true that a genuine nutrient deficiency is behind at least some of the cases of ADHD.
Researchers publishing their findings in the December 30, 2013, issue of BMC Pediatrics note that among children with ADHD diagnoses, sleep disturbances are more likely to occur in children with lower serum levels of ferritin (iron). Earlier in 2013, researchers writing in the Journal of Child and Adolescent Psychopharmacology demonstrated that the iron levels of children and teens receiving services at a community mental health clinic were lower than the national average for children of the same age. The researchers commented, "Compromised iron status may be an additional biological risk factor for cognitive, behavioral, and psychiatric problems in pediatric populations."
Israeli researchers tell the same story: in an article published in September 2011, a team of scientists found that children with ADHD diagnoses were more likely than not to have low iron levels.
Spanish researchers report similar findings, this time with respect to treating ADHD: in a Spanish-language pediatric journal article published in October 2013, scientists note the successful treatment of a subgroup of iron-deficient ADHD patients with iron supplements. They remark that the inattentive subtype of ADHD was particularly amenable to treatment with iron supplements.
What about overall? Have scientists noticed a link between iron deficiency and ADHD in the population as a whole? Two different reviews of the literature yield similar results: researchers at the Child Study Center of the NYU Langone Medical Center in Manhattan and Italian geneticists agree that children with low levels of serum ferritin appear to have an increased chance of being diagnosed with ADHD. A very large study (more than 700 participants) in Turkey with results published in October 2012 had similar results. The NYU researchers involved in the aforementioned meta-analysis additionally assert that research should move from its current focus on serum ferritin (blood iron levels) "towards a more comprehensive and translational investigation of iron in ADHD."
Indeed, one may be prompted by these recent developments to wonder about the mechanism behind the illness. A Korean research team found an association between transferrin levels and ADHD, suggesting that this iron-binding glycoprotein might be lacking in some individuals afflicted with ADHD. This is perhaps unsurprising to those aware that ADHD is a comorbid condition in 25 percent of children with restless legs syndrome, a disorder believed to be linked to improper iron regulation. Further research into treatments that address the root causes of ADHD and other disorders of iron regulation will be welcomed by the community of individuals suffering from these conditions.