Drinking Water with Higher Levels of Lithium Linked to Autism Risk


Recent research, spearheaded by a UCLA Health investigator, reveals that expectant mothers whose homes had higher concentrations of lithium in their tap water were at a slightly elevated risk of their children being diagnosed with autism spectrum disorder.

The study, published in JAMA Pediatrics, suggests that naturally occurring lithium in drinking water could be a potential environmental hazard linked to autism. It is reportedly the first of its kind to make this association.

Beate Ritz, MD, PhD, who is a professor of neurology at the David Geffen School of Medicine at UCLA and holds a position in epidemiology and environmental health at the UCLA Fielding School of Public Health, emphasized in a statement that "Any drinking water contaminants that may affect the developing human brain deserve intense scrutiny." 

Ritz noted that the increasing use and disposal of lithium batteries could lead to anthropogenic sources of lithium in water and potentially increase the risk of groundwater contamination. She further mentioned that the study's results were based on high-quality Danish data, and further replication in other regions and populations is necessary.

Lithium's mood-stabilizing properties have made specific lithium compounds a standard treatment option for depression and bipolar disorders. Despite this, there has been considerable discussion regarding the safety of taking lithium during pregnancy, given emerging evidence linking its usage to an increased risk of cardiac anomalies or defects in newborns and a higher risk of miscarriage.

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Ritz, whose research delves into the impact of environmental exposures on neurodegenerative diseases and neurodevelopmental disorders, decided to investigate the potential link between lithium and autism risk because there was limited research on how lithium can influence brain growth and development in humans. Her interest was piqued by specific experimental research findings that suggested lithium, one of several naturally occurring metals commonly present in water, may influence a vital molecular pathway that plays a role in both neurodevelopment and autism.

Study co-author Zeyan Liew, PhD, MPH, Assistant Professor of Epidemiology at the Yale University School of Public Health, highlighted the significance of the study by noting that although previous research using high-quality medical registry data in Denmark revealed that chronic and low-dose lithium consumption from drinking water can impact the onset of adult neuropsychiatric disorders, no study had yet examined the impact of drinking water with lithium on neurodevelopment in pregnant women's offspring.

The findings of this study are useful to integrative practitioners who may need to consider the potential risks associated with drinking water containing lithium during pregnancy when evaluating a patient's overall health and counseling them on prenatal care.

Ritz, Liew, and researchers from Denmark analyzed lithium levels in 151 public waterworks that supplied water to approximately half of the country's population. They used information from Denmark's civil registry system to identify the specific waterworks that provided water to the mothers during their pregnancy. Using a nationwide database of patients with psychiatric disorders, the researchers identified children born between 1997 and 2013 and compared 12,799 children diagnosed with autism to 63,681 children with no autism diagnosis. The researchers also accounted for various maternal characteristics, socioeconomic factors, and air pollution exposures previously associated with an increased risk of autism in children.

The research team noted a link between increasing lithium levels and the likelihood of an autism diagnosis. Compared to people with lithium levels in the lowest quartile (twenty-fifth percentile), those with groups in the second and third quartiles had a 24 to 25 percent higher risk of autism. The highest quartile of lithium levels was associated with a 46 percent higher risk of autism diagnosis than the lowest quartile.

Upon further analysis of the data, the researchers discovered a close connection between higher levels of lithium and an elevated risk of autism diagnosis, even when considering subtypes of the disorder. Additionally, the researchers observed that the relationship between lithium levels and autism risk was slightly more pronounced among urban people than in smaller towns and rural regions.

Denmark was an ideal location for conducting this study due to various factors. First, the country's comprehensive civil databases have proven highly useful for public health researchers. Additionally, Denmark has a low rate of bottled water consumption in Europe, indicating a greater reliance on tap water and a reliable system for detecting trace metals and contaminants in its water supply. According to Ritz, Denmark's water supply likely has low to moderate lithium levels compared to other countries.