A combined study from Yale and Aarhus University in Denmark examined the possible link between lithium levels in drinking water and the increased risk of autism in children. It is not yet possible to say with definitive certainty that lithium is the direct cause of autism, but this discovery certainly deserves further investigation. Lithium, often used as a drug to treat mood disorders, has in the past been linked to heart defects in newborns and miscarriages.
Pioneering research on autism and lithium
It is the first time that an association has been discovered between lithium and autism spectrum disorders (ASD). Danish research analyzed 52.706 children and found that mothers' exposure to higher levels of lithium in drinking water during pregnancy was associated with a moderate increase in the risk of ASD in their children. Lithium usually ends up in drinking water through the erosion of underground minerals. In Denmark, lithium levels in water are on average low compared to other countries.
The scientists used data from 151 different public water plants (around 50% coverage of the entire Danish population). They then divided lithium concentrations in drinking water into four equal parts and analyzed prenatal lithium exposure for each quartile. In the second and third quartiles, the risk of being diagnosed with autism was 24-26% higher than the lowest quartile. In the top quartile, the risk even increased by 46%.
Lithium, drinking water and autism: the next steps
The picture seems rather complex. As mentioned, lithium is used as a mood stabilizer to treat people with bipolar disorders and depression. Previous studies have linked higher levels of lithium in drinking water to lower suicide rates, leading some to argue (crazy to me) that the element it could be artificially added to water supplies.
The Danish study will take other steps to bring the situation into focus. To evaluate the exposure of mothers, for example, it will be necessary to also include data on actual water consumption as well as on the presence of lithium alone. In summary, the research has opened a new door on the possible link between lithium in drinking water and autism. Any contaminant in drinking water that may affect the developing human brain deserves full attention.
The study was published in Jama Pediatrics (I link it here)
