Does soy-based infant formula cause ADHD? Update and public policy considerations.

An earlier article hypothesized a relationship between soy-based infant formulas, manganese (Mn) neurotoxicity and symptoms of ADHD. In this update, more recent literature on ADHD, Mn and Mn neurotoxicity is reviewed, as well as the risks of Mn toxicity that may accompany ingestion of soy-based infant formula. The results of several critical studies are described, including rodent and primate models that demonstrate an association between ingestion of relatively high levels of Mn and: overactivity, disinhibition and inattention; stereotypes and disturbances of social relatedness; and alterations of dopamine D1 and D2 receptors and dopamine transporter in critical brain regions.

A 30-year prospective follow-up study of hyperactive boys with conduct problems: adult criminality.

Objective: To compare the official arrest records for a large number of hyperactive boys (N = 179), most with conduct problems, and 75 control boys; to examine childhood IQ, socioeconomic status, and parent reports of childhood hyperactivity and conduct problems for their contribution to criminal behavior in adulthood; and to compare adult outcome for multimodality-treated (MMT) and drug-treated-only (DTO) hyperactives.

Method: We report on the official arrest history from early to mid- (18 to 38 years of age) adulthood in these 254 white subjects.

Results: Ninety one percent of subjects were followed up.

Prenatal manganese levels linked to childhood behavioral disinhibition.

Although manganese (Mn) is an essential mineral, high concentrations of the metal can result in a neurotoxic syndrome affecting dopamine balance and behavior control. We report an exploratory study showing an association between Mn deposits in tooth enamel, dating to the 20th and 62-64th gestational weeks, and childhood behavioral outcomes. In a sample of 27 children, 20th week Mn level was significantly and positively correlated with measures of behavioral disinhibition, specifically, play with a forbidden toy (36 months), impulsive errors on a continuous performance and a children's Stroop test (54 months), parents' and teachers' ratings of externalizing and attention problems on the Child Behavior Checklist (1st and 3rd grades), and teacher ratings on the Disruptive Behavior Disorders Scale (3rd grade).

Neurobehavioral evaluation of rhesus monkey infants fed cow's milk formula, soy formula, or soy formula with added manganese.

The possible neurobehavioral effects of excess manganese in soy formula were studied. Male rhesus monkeys (n=8/group) were fed a commercial cow's milk based formula (Control), a commercial soy protein based formula (Soy), or the soy formula with added manganese (Soy+Mn) from birth to 4 months of age. Soy formulas naturally have higher manganese (Mn) content than cow's milk formulas.

Why children with ADHD do not have low IQs.

The major cognitive deficit of children with attention-deficit/hyperactivity disorder (ADHD) is impaired executive function (EF), a cognitive component that some theorists believe to be the primary substrate for the general intelligence (g) factor. We review the constructs of g and EF and the relevant research findings on ADHD. We then analyze the results of a battery of diverse tests, including measures of EF, administered to 123 boys with ADHD.

End-of-life care for a man with developmental disabilities.

Background: Science can artificially maintain many essential life functions. Does such care prolong life or dying?

Methods: A case is described of a patient with developmental disability with unknown health care choices who was hospitalized for drug-resistant urosepsis. He developed aspiration pneumonia, deep vein thrombosis, and respiratory arrest.

Effects of neonatal dietary manganese exposure on brain dopamine levels and neurocognitive functions.

Neonatal exposure to high levels of manganese (Mn) has been indirectly implicated as a causal agent in attention deficit hyperactivity disorder (ADHD), since Mn toxicity and ADHD both involve dysfunction in brain dopamine (DA) systems. This study was undertaken to examine this putative relationship in an animal model by determining if levels of neonatal dietary Mn exposure were related to brain DA levels and/or behavioral tests of executive function (EF) when the animals reached maturity. We used 32 newborn male Sprague-Dawley rats and randomly assigned them to one of the four dietary Mn supplementation conditions: 0, 50, 250 and 500 microg per day, administered daily in water from postnatal days 1-21.

Effect of high dietary manganese intake of neonatal rats on tissue mineral accumulation, striatal dopamine levels, and neurodevelopmental status.

Mn is an essential element, but may become neurotoxic at high levels. Recent reports of high Mn levels in hair of children with neurodevelopmental deficits suggest that these deficits could be due to Mn-induced neurotoxic effects on brain dopamine (DA) systems, although the mechanism is not well understood. Infant formulas contain considerably higher concentrations of Mn than human milk.

Carbamazepine reduces dopamine-mediated behavior in chronic neuroleptic-treated and untreated rats: implications for treatment of tardive dyskinesia and hyperdopaminergic states.

Chronic treatment with neuroleptic drugs such as haloperidol (HAL) can result in a syndrome of abnormal involuntary movements known as tardive dyskinesia (TD). The authors have obtained evidence that TD in humans is reduced in patients also taking anticonvulsant drugs, primarily carbamazepine (CBZ). To test for a causal role of CBZ in this effect, the authors quantified abnormal movements elicited by dopamine (DA) receptor stimulation in rats (Rattus norvegius) withdrawn from chronic treatment with HAL or CBZ alone or in combination.