Using weed during pregnancy linked to psychotic-like behaviors in children, study finds

(CNN) If you're one of the growing numbers of women who use weed while pregnant, think twice: A new study found it may increase psychotic-like behaviors in children.

The study, published Wednesday in JAMA Psychiatry , analyzed data on 11,489 children who were followed as part of the Adolescent Brain Cognitive Development (ABCD) study, which says it's the "largest long-term study of brain development and child health in the United States." The children's cognitive and behavior patterns were evaluated in middle childhood, around age 9.

Of those children, 655 were exposed to cannabis while in utero, according to statements from the mothers. Compared to the 10,834 children with no exposure, children whose mothers had used during pregnancy were more likely to have psychotic-like behaviors and more attention, social and sleep problems, as well as weaker cognitive abilities.

If the woman continued to use after she discovered she was pregnant, the negative effects were more pronounced, the study found, and stayed after adjusting for confounding variables.

"Use of cannabis despite knowledge of pregnancy might represent a preexisting and more severe form of cannabis use," the authors wrote.