الفهرس 
Attention Defcit Hyperactivity Disorder (ADHD)Only 14 pages are availabe for public view
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Abstract
A
DHD has increased in prevalence over the past several years leading many to look for environmental factors responsible for this rise.
The major goal of the present study was to examine the relationship between the incidence of ADHD and serum Mn levels in school aged children. The study comprised 40 children with ADHD and 20 controls, all of whom are living in and around Cairo city.
The results of the conducted study showed that children with ADHD had higher serum Mn levels than controls. The mean Mn serum levels in children with ADHD was (5.5ug/L) compared to (4.1ug/L) in the control group which is significantly higher statistically (P<0.01). Both groups had higher serum Mn levels than the previously recorded reference values (3.3ug/L) by Farias et al. (2010). No significant differences in both males and females concerning serum Mn levels were found (P>0.05).
There was also a positive and strong statistically significant association between serum Mn levels in ADHD children and hyperactive behavior (P<0.01), total externalizing symptoms (P<0.01), aggressive behavior (P<0.01), rule breaking behavior (P<0.01), ODD (P<0.01) and peer conflict (P<0.01).
In the conducted study, our results showed that compared to the control group, the study group had lower IQ scores but wasn’t statistically significant (P>0.05).
from the findings in this study, we believe that reference serum Mn levels in children should be standardized internationally, so that we could detect serum Mn levels above which children are at risk of neurotoxic effects of Mn.
Although our results must be interpreted with caution due to the small sample number, it still indicates that high serum Mn levels in children could predispose to and/or aggravate ADHD symptoms and suggests that many children are at risk of neurological consequences of low/moderate Mn exposure.
These results also show the necessity of further investigations on the relationship between serum Mn levels and ADHD to better understand the health impact of exposure to environmental contaminants as Mn.
We suggest that further studies should be done for follow up and verifying whether the behavioral problems of these children would persist once serum Mn levels are reduced or not. We also suggest that further studies should measure both Mn and Fe serum levels in children to assess whether Fe deficiency could be a contributing factor to high serum Mn levels or not. In addition, school children should be routinely screened for high serum Mn level to avoid the harmful effects of being subjected to subtoxic Mn levels.
The present study highlights the importance of understanding the health effects of Mn over exposure particularly during potentially sensitive stages of early development beginning with the fetal stage.
Finally, considering the prevalence, seriousness and impact of ADHD on affected children and their parents with negative consequences on scholastic performance and adult mental health outcomes, we believe that efforts from international institutions such as the WHO and most importantly national efforts, guidelines and preventive measures involving heavy metal exposure should receive sufficient attention.