Substance use during pregnancy raises ADHD risk in children, study finds

March 11 (UPI) -- Use of tobacco, opioids, alcohol and other substances during pregnancy increases the risk that newborns will develop attention-deficit/hyperactivity disorder as they age, a study published Friday by JAMA Network Open found.

Children whose mothers used opioids during pregnancy, for example, had more than double the risk for attention-deficit/hyperactivity disorder, or ADHD, compared to those whose mothers avoided the drugs, the data showed.

Opioids include prescription pain medications such as oxycontin and morphine, as well as illegal drugs such as heroin and opium, according to the National Institute on Drug Abuse.

People who used more than one substance during pregnancy, combining tobacco and marijuana or opioids and alcohol, for example, raised their child's risk for developing ADHD by nearly 50%, the researchers said.

This "study found that any increase in the number of substances used during [pregnancy] was associated with increases in the risk of developing ADHD in later childhood," wrote researchers from Johns Hopkins Bloomberg School of Public Health in Baltimore, among others.

"Exposures to opioids combined with cannabis and opioids combined with tobacco smoking were of particular concern," they said.

However, combining alcohol with any of these substances also increased the risk, they added.

Earlier studies have linked gestational diabetes, or diabetes developed during pregnancy, with increased risk for ADHD, among other mental health disorders, in children.

ADHD is a neurodevelopmental disorder that causes inattention, hyperactivity and poor impulse control, according to the Centers for Disease Control and Prevention.

Some people with ADHD also have difficulty regulating emotions and problems with learning and memory, the agency says.

At least 6 million children in the United States have been diagnosed with ADHD, the CDC estimates, and their symptoms can continue into adulthood, even with treatment.

The findings of this study are based on an analysis of data for more than 3,100 children and their mothers, the researchers said.

Just under 500 of the children, or 16%, were diagnosed with ADHD at some point during childhood, according to the researchers.

Roughly one in four of the mothers in the study reported using at least one substance during pregnancy, though this figure was higher -- just over 30% -- among those whose children developed ADHD, the data showed.

Tobacco and alcohol were the most common substances used during pregnancy among the study participants, the researchers said.

Marijuana use during pregnancy increased the risk for ADHD among children by more than 40%, while alcohol consumption boosted the risk by 15%, they said.

"These findings have public health implications for addressing polysubstance exposure among children during [pregnancy]," the researchers wrote.

"Future work is needed to identify potential mechanisms through which substances interact," they said.