Navigation Links
Study says lead may be the culprit in ADHD
Date:1/28/2010

ADHD, or attention-deficit/hyperactivity disorder, is among the costliest of behavioral disorders. Its combination of inattention, impulsivity and hyperactivity leads to accidental injuries, school failure, substance abuse, antisocial behavior and more. Yet despite nearly a century of study, the disorder's roots remain mysterious.

Much of modern ADHD research has focused on heritability of the condition, and indeed evidence suggests that genes may account for as much as 70 percent of hyperactivity and inattention in children. But that leaves 30 percent unexplained, so recently the focus has shifted to the environment. What is it that triggers an underlying susceptibility and changes it into a full-blown disorder? New research suggests that the culprit may be an old villainleadand what's more it explains the causal pathway from exposure to disability.

Lead is a neurotoxin. This has been known for a long time, and in fact government regulation drastically reduced environmental lead a generation ago. But regulating automobile fuel and paint didn't entirely eliminate lead from the environment. It's found in trace amounts in everything from children's costume jewelry to imported candies to soil and drinking water. Every American today is exposed to low levels of the metal, and indeed nearly all children have measureable levels of lead in their bodies. According to psychological scientist Joel Nigg of the Oregon Health & Science University, this universal low-level exposure makes lead an ideal candidate for the disorder's trigger.

This was just a theory until quite recently, but two recent studies now provide strong evidence. The first study compared children formally diagnosed with ADHD to controls, and found that the children with the disorder had slightly higher levels of lead in their blood. This study showed a link only between blood lead and hyperactivity/impulsivity symptoms, not inattention. But a second study showed a robust link between blood lead and both parent and teacher ratings of ADHD symptoms, including both hyperactivity and attention problems. In both studies, the connection was independent of IQ, family income, race, or maternal smoking during pregnancy.

Nigg offers a causal model for the disabling symptoms associated with ADHD: Lead attaches to sites in the brain's striatum and frontal cortex, where it acts on the genes in these regionscausing them to turn on or remain inactive. Gene activity shapes the development and activity of these brain regions. By disrupting brain activity, the toxin in turn alters psychological processes supported by these neurons, notably cognitive control. Finally, diminished cognitive control contributes to hyperactivity and lack of vigilance. Nigg describes his new data and his explanatory model in the February issue of the journal Current Directions in Psychological Science.


'/>"/>

Contact: Catherine Allen-West
cwest@psychologicalscience.org
202-293-9300
Association for Psychological Science
Source:Eurekalert

Related medicine news :

1. Penn study finds pro-death proteins required to regulate healthy immune function
2. New study shows promise in reducing surgical risks associated with surgical bleeding
3. Study, meta-analysis examine factors associated with death from heatstroke
4. Study suggests loss of 2 types of neurons -- not just 1 -- triggers Parkinsons symptoms
5. Study says COPD testing is not measuring up
6. Preclinical study suggests organ-transplant drug may aid in lupus fight
7. Ability to cope with stress can increase good cholesterol in older white men, study finds
8. High alcohol consumption increases stroke risk, Tulane study says
9. Mailman School of Public Health study examines link between racial discrimination and substance use
10. Pitt study finds inequality in tobacco advertising
11. Stanford study highlights cost-effective method of lowering heart disease risks
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/18/2017)... Dallas, Texas (PRWEB) , ... February 17, 2017 , ... ... Arden Moore’s “Oh Behave” Show on the Pet Life Radio network. The episode, ... explores a number of topics including: what factors led to Park Cities Pet Sitter’s ...
(Date:2/17/2017)... Murfreesboro, TN (PRWEB) , ... February 17, 2017 ... ... EHR mobility has not kept pace. Enovate Medical has introduced an innovative workstation ... 20 years of supporting nurses, the Encore Mobile EHR Workstation offers a lightweight, ...
(Date:2/17/2017)... (PRWEB) , ... February 17, ... ... Device Approval and Reimbursement , **An FDAnews Webinar**, Feb. 22, 2017 — ... are the critical reimbursement questions manufacturers should be asking before selecting an ...
(Date:2/17/2017)... (PRWEB) , ... February 17, 2017 , ... ... at the HIMSS17 Conference & Exhibition in Orlando, Fla., February 19-23. Visitors to ... of the most widely used electronic patient signatures solution in healthcare . ...
(Date:2/17/2017)... ... February 17, 2017 , ... PrideStaff, ... George Rogers, was named to Staffing Industry Analysts' 2017 "Staffing 100 North America" ... who have made notable contributions to the staffing industry over the last twelve ...
Breaking Medicine News(10 mins):
(Date:2/17/2017)... 17, 2017  BioDigital, Inc., creators of the ... their 3D body mapping technology with eClinicalWorks, a ... integration will be used to capture and present ... the human body. BioDigital pilots show using a ... also increasing the precision of clinical annotations compared ...
(Date:2/17/2017)... YORK , Feb. 17, 2017  Noble Capital ... on ESSA Pharma Inc. (Nasdaq: EPIX ). ... Research, Kumar Raja , PhD. ESSA ... for castration resistant prostate cancer (CRPC). Its lead compound ... blocks the amino-terminal domain of the androgen receptor, thereby ...
(Date:2/16/2017)... Research and Markets has announced the ... Technologies" report to their offering. ... Traditional medical devices include ... non-drug coated implantables, large endoscopes, needle based drug delivery, lab ... last two to three decades for the treatment and management ...
Breaking Medicine Technology: