MENTAL HEALTH EFFECTS OF CHILDHOOD LEAD EXPOSURE

For developing brains and bodies, lead exposure can be devastating in a variety of ways. The CDC warns that childhood exposure to lead increases the risk of:

• Brain and nervous system damage
• Impaired growth and development
• Learning and behavior problems, including lower IQ, attention-deficit/hyperactivity disorder (ADHD), and criminal behavior
• Problems with hearing and speech

Researchers have been studying the mental health effects of lead exposure for decades. One long-term study, which tracked 579 children from New Zealand over more than 30 years, examined the link between lead exposure in childhood and mental health effects in adulthood.

Lead exposure had already been established as disrupting the behavioral development of children who were exposed, but researchers wanted to pinpoint its lasting effects. They found that with more lead exposure in childhood, individuals were more likely to exhibit mental illness across their lifetimes, as well as challenging personality traits in adulthood.

Increased levels of lead in blood were associated with increased mental health symptoms, especially internalizing and thought disorders. And personality tests revealed higher lead levels were related to increased neuroticism, as well as a decrease in agreeableness and conscientiousness.

In other words, researchers concluded, childhood exposure could have a lifelong impact on mental health and even personality.

A 2019 article in JAMA that evaluated this study added that previous research had linked prenatal or childhood lead exposure with greater risk for mental health issues in adulthood, including schizophrenia and antisocial behavior.

But the New Zealand children studied were of particular interest because their birthplace registered “some of the highest gasoline lead levels in the world,” according to the article. Therefore, unusually high levels of lead contaminated the air and soil through the exhaust from automobiles.

These same children were also shown, in a separate study, to experience negative health outcomes when tested in adulthood, at 38 years old. Their increased lead exposures were associated with more significant declines in both IQ and occupational socioeconomic status, which itself can further impact health.

LEAD EXPOSURE AND MENTAL HEALTH IN ADULTS

It’s important to look at how lead exposure affects mental health. In 1999, a five-year study evaluated the connection between lead levels in blood and three common mental health concerns: major depressive, panic, and generalized anxiety disorders. The results showed that higher lead levels in blood increased the odds of depression and panic disorder.

Related: 10 Scary Ways Toxins Poison Your Brain

Those with the highest lead levels were 2.3 times more likely to have depression and 4.9 times more likely to develop a panic disorder, compared to subjects with the lowest levels. Higher lead levels did not show the same association with generalized anxiety disorder.

The nearly 2,000 participants were young adults (20-39 years old) who were considered to have low levels of exposure. Therefore, researchers concluded that lead exposure “at levels generally considered safe could result in adverse mental health outcomes.”

The World Health Organization (WHO) reports that lead causes devastating health impacts globally. Lead contaminates the environment through activities like mining and manufacturing, and it’s present in products from paints and toys to cosmetics and jewelry. It can even be found in drinking water.

The WHO lists numerous harms caused by this heavy metal, including:

• Increased risk of high blood pressure
• Cardiovascular problems
• Kidney damage
• Reduced fetal growth and premature birth among pregnant women

• Severe damage to the brain and central nervous system, causing coma, convulsions and even death (with high levels of exposure)
• Compromised brain development, resulting in reduced IQ and behavioral changes, including reduced attention span
• Anemia
• Hypertension
• Immunotoxicity
• Toxicity of the reproductive organs

Ultimately, environmental toxins like lead will steal your mind over time. A toxic brain, as shown in SPECT scans, tends to have a scalloped appearance, with decreased overall activity and blood flow. And because the symptoms of neurotoxicity from lead and other dangerous substances may mimic other conditions, this issue can easily be misdiagnosed or undiagnosed.

Related: 23 Everyday Toxins That Destroy Thinking

LEADED GASOLINE AND MENTAL ILLNESS

An article in 2024 noted that exposure to leaded gasoline affected millions of Americans, creating long-term impacts on mental health and personality changes. Generation X (those born between the mid-1960s and early 1980s) showed the greatest related risks for mental health issues like anxiety, depression, and ADHD.

The article also pointed to the possible connection between falling crime rates and reduced lead exposure in the 1990s and 2000s. This theory, known as the lead-crime hypothesis, links criminal behavior (including homicide) and lead exposure.

Authors cited a 2022 study with alarming stats regarding lead exposure in the United States. It estimated that more than 170 million Americans alive were exposed to high lead levels in early childhood. And several million of them “were exposed to five-plus times the current reference level.”

Leaded gasoline significantly contributed to these high exposure levels. The article explained that this increase could trigger “an estimated 151 million additional mental disorders, including heightened risks for anxiety, depression, and attention-deficit/hyperactivity disorder (ADHD).”

Authors called for more lead screening, particularly among children, and psychiatric recognition of lead poisoning as a neurodevelopmental disorder. With more awareness, they hope for increased efforts toward both prevention and intervention.

HEALING A TOXIC BRAIN

While lead poisoning at any age is devastating, there are steps you can take to heal if you suspect toxin exposure.