The first study to look at methamphetamine’s potential lasting effects on children whose mothers used it in pregnancy finds these kids at higher risk for behavior problems than other children.

The behavior differences - anxiety, depression, moodiness - weren’t huge, but lead researcher Linda LaGasse called them “very worrisome.”

Methamphetamine is a stimulant like crack cocaine, and earlier research showed meth babies have similarities to so-called “crack babies” - smaller in size and prone to drowsiness and stress. Results in long-term studies conflict on whether children of cocaine-using mothers have lasting behavior problems.

Whether problems persist in young children of meth users is unknown. But LaGasse, who does research at Brown University’s Center of the Study of Children at Risk, said methamphetamine has stronger effects on the brain so it may be more likely to cause lasting effects in children.

The study was published online Monday in Pediatrics. The National Institutes of Health paid for the research, including a grant from the National Institute on Drug Abuse.

Government data suggest more than 10 million Americans have used meth; fewer than 1 percent of pregnant women are users.

Joseph Frascella, who heads a behavioral division at the National Institute on Drug Abuse, said the research is among “groundbreaking” studies examining effects of substance abuse during pregnancy.

But because the study is a first, the results should be viewed cautiously and need to be repeated, he said.

The study of children tracked from age 3 through 5 builds on earlier research by LaGasse on the same group - 330 youngsters tracked in the Midwest and West, areas where meth use is most common. Mothers were recruited shortly after giving birth in Des Moines, Iowa; Honolulu, Los Angeles, and Tulsa, Okla. They were asked about prenatal meth use and newborns’ stools were tested for evidence of the drug. Effects in children exposed to the drug were compared with those whose mothers didn’t use meth. Both groups were high-risk children, with many living in disadvantaged homes.

Mothers or other caregivers completed a widely used checklist asking how often kids showed many kinds of troublesome behavior.

At age 3, scores for anxiety, depression and moodiness were slightly higher in meth-users’ children. These differences persisted at age 5. The older children who’d been exposed to meth also had more aggression and attention problems similar to ADHD, attention deficit hyperactivity disorder. Mothers were asked about symptoms, but not if their kids had ever been diagnosed with behavior disorders.

More than half of the mothers who’d used meth during pregnancy also used it afterwards. These women also were more likely to use other drugs during and after pregnancy and to be single mothers. But the researchers said accounting for those differences and others in the two groups’ family lives didn’t change the results. (AP)