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L. Eugene Arnold, professor emeritus in psychiatry

Posted on | August 11, 2010 | 1,714 views | Comments Off

Are there more instances of childhood ADHD today, and if so, what are some of the causes?

There may be more ADHD cases now than 100 years ago, but part of the apparent increase is better recognition. In the past only the most severe cases were recognized (e.g., Still’s syndrome, von Economo’s encephalitis sequelae, “minimal brain damage”).  Now, more moderate and even mild cases are recognized, some of which are genetic variants that might have actually been an advantage in the pre-industrial ages, especially for hunter-gatherers.

This brings us to reasons for some of the suspected real increase. One of these is a change in culture from an agricultural society to information society. A century ago, the majority of American children attended a one-room school, an ideal setting for someone genetically predisposed to ADHD. The individualized lessons, tutoring by older kids, opportunity to learn by teaching younger ones, breaks for chores like stoking the fire, carrying in wood, cleaning erasers, etc., and close communication and cooperation between home and school provided a “natural treatment” environment in which the child could succeed. Further, for those who did not do so well in school even with all those supports, there were opportunities to succeed as adults without literacy.

Other possible reasons for an increase in ADHD include the interaction of genetic vulnerability with modern stresses and environmental toxins, such as heavy metals, insecticides and chemicals used in building materials, cars, clothes, lawn care, food packaging and even food processing. Changes in amount of exercise and in the normative diet may also be an issue. Even for those eating a 19th-century diet, the vitamin and mineral content of the various foods may have changed with agricultural practices.

Is over-prescription of ADHD medicine a problem among children? If so, then why?

The dramatic increase in prescriptions for ADHD since 1990 may or may not reflect overprescription, depending on whether there was previously underprescription or whether there has been an increase in need. The real questions are whether those who are receiving the medication are correctly diagnosed and whether they are benefitting.  Probably some who should have medication are not getting it and others who should not be taking it are. Many diagnoses are made on the basis of symptom count without considering other reasons for the symptoms, which can be mimicked by many other disorders. Even with a correct diagnosis, some individuals respond to a given medicine and others do not. Those who do not respond to one may respond to another. Further, the optimal dose for an individual varies widely. Therefore it is important to “titrate” dosage, monitor results and if necessary try more than one medication to be sure an individual is benefitting.

How do ADHD medicines work, and are there alternative methods to treat it?

Most of them work by increasing adrenergic neurotransmission by neurochemicals like dopamine and norepinephrine (noradrenaline). The two best-studied are the stimulants amphetamine and methylphenidate, which mainly work on dopamine. However, there are two FDA-approved nonstimulants for ADHD that work more through norepinephrine. At OSU Nisonger Center we are currently studying one of these, atomoxetine, for children with both ADHD and autism. We also are studying another one, guanfacine XR, for treatment of both child and adolescent ADHD up to age 17. For children with ADHD who also have a problem with anger, we are trying yet a fifth kind of medication, along with stimulant and parent training. For more details about these treatment studies, visit psychmed.osu.edu.

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