A study released last week shows children and adolescents face an increased risk of mental disorder if their mothers used marijuana during pregnancy.

The study published in JAMA Pediatrics analyzed longitudinal data about the effects of marijuana use from the ongoing Adolescent Brain Cognitive Development (ABCD) Study. The ABCD Study tracks brain development and health in nearly 12,000 youth as they grow into young adults.

The new research found marijuana use during pregnancy is associated with attention, social, and behavioral problems that last as children enter early adolescence and may put children at an increased risk of mental disorders and substance use as they grow older.

The NIH has noted that marijuana use among pregnant women has increased from 3% in 2002 to 5.4% in 2019.

A growing body of research shows marijuana is harmful to unborn babies, children, adolescents, and young adults.

Last year a study out of California found infants were 35% more likely to die within a year of birth if their mother used marijuana heavily.

The study also found that infants were more likely to be born preterm, have a low birth weight, and be small for their gestational age.

In June, The New York Times reported the story of a teenage girl who could not stop fainting and throwing up after becoming addicted to vaping high-potency marijuana.

Marijuana can have damaging effects on adolescent brains — including permanent loss in IQ, difficulty thinking and problem-solving, reduced coordination, and increased risk of psychosis.

2019 study found using marijuana with THC levels exceeding 10% increased the odds of a psychotic episode.

Another study published in the Canadian Medical Association Journal last year found adults under age 45 who frequently used marijuana were roughly twice as likely to suffer heart attack as adults who did not use marijuana.

A report published in the Journal of the American Medical Association found that states that legalized commercial marijuana sales saw self-harm rates rise by 46% among men ages 21 to 39.

In Colorado, authorities report that traffic deaths involving drivers who tested positive for marijuana have increased 138% since marijuana was legalized in 2012. Research shows Canada saw a dramatic increase in driving while high following legalization of marijuana in 2018.

The list goes on and on.

All of this underscores what we have said for years: Marijuana may be many things, but “harmless” simply is not one of them.