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Updated: May 30, 2026
Long-term Behavioral and Reproductive Consequences of Embryonic Exposure to Low-dose Toxicants
Published on: March 6, 2018
Thimerosal exposure in early life and neuropsychological outcomes 7-10 years later
John P Barile1, Gabriel P Kuperminc, Eric S Weintraub
1Department of Psychology, Georgia State University, USA. jbarile@cdc.gov
Insights
This study found no significant links between early thimerosal vaccine exposure and most child neuropsychological outcomes. A small association was noted with tics in boys, but requires cautious interpretation.
Area of Science:
- Neuroscience
- Pediatric Health
- Vaccine Safety Research
Background:
- Thimerosal, a mercury-based preservative, has been used in vaccines.
- Concerns exist regarding potential neurodevelopmental effects of early-life thimerosal exposure.
Purpose of the Study:
- To investigate associations between early thimerosal-containing vaccine and immune globulin exposure and neuropsychological outcomes in children aged 7-10 years.
- To analyze potential links between thimerosal exposure and neurodevelopmental factors.
Main Methods:
- Utilized a public use dataset of 1,047 children (ages 7-10) and their mothers.
- Developed seven latent neuropsychological factors and performed regression analyses with thimerosal exposure variables and covariates.
Main Results:
- No statistically significant associations were found between early thimerosal exposure and six of seven latent neuropsychological factors.
- A small, statistically significant association was observed between early thimerosal exposure and the presence of tics in boys.
Conclusions:
- The observed association between thimerosal exposure and tics in boys should be interpreted cautiously.
- Limitations in tic measurement and biological plausibility warrant further investigation into this specific finding.
Objective:
The authors used a public use data set to investigate associations between the receipt of thimerosal-containing vaccines and immune globulins early in life and neuropsychological outcomes assessed at 7-10 years.
Methods:
The data were originally created by evaluating 1,047 children ages 7-10 years and their biological mothers. This study developed seven latent neuropsychological factors and regressed them on a comprehensive set of covariates and thimerosal exposure variables.
Results:
The authors found no statistically significant associations between thimerosal exposure from vaccines early in life and six of the seven latent constructs. There was a small, but statistically significant association between early thimerosal exposure and the presence of tics in boys.
Conclusions:
This finding should be interpreted with caution due to limitations in the measurement of tics and the limited biological plausibility regarding a causal relationship.
