Heavy Metal and Thiol/Disulfide in Children with Attention-Deficit and Hyperactivity Disorder

Area of Science:

• Neuroscience
• Environmental Health
• Pediatrics

Background:

• Oxidative stress and heavy metal exposure are debated factors in attention-deficit/hyperactivity disorder (ADHD) etiology.
• This study investigates heavy metal levels and oxidative balance in newly diagnosed ADHD patients.

Purpose of the Study:

• To examine heavy metal (lead, mercury, cadmium) levels in children with ADHD.
• To assess oxidative balance by measuring thiol and disulfide levels.
• To determine the relationship between heavy metal exposure and oxidative balance in ADHD.

Main Methods:

• Included 35 newly diagnosed ADHD patients and 31 healthy controls.
• Collected data on breastfeeding, prenatal, and postnatal smoking exposures.
• Measured lead, mercury, and cadmium using inductively coupled plasma optical emission spectroscopy.
• Quantified serum thiol and disulfide levels using automated spectrophotometry.

Main Results:

• ADHD group had higher rates of prenatal smoking exposure (P=.030).
• Significantly higher native and total thiol levels were observed in children with ADHD (P<.001).
• Elevated mercury (Hg) levels were found in the ADHD group (P=.002), while cadmium levels were higher in controls (P<.001).
• No significant difference in lead (Pb) levels between groups (P=.844).

Conclusions:

• Mercury exposure and prenatal smoking may contribute to childhood ADHD development.
• Children with ADHD might exhibit enhanced antioxidant levels as a response to oxidative stress.