fMRI study will analyze marijuana’s effect on the infant brain

A team of radiologists at the University of Washington School of Medicine in Seattle will utilize fMRI, along with formal evaluations to study the effects of cannabis on infant brain development.

The “Moms+Marijuana” study will track mother’s marijuana use from the first trimester throughout pregnancy, scanning their infant’s brains at six months to determine effects of cannabis exposure without influence of additional substances such as alcohol, tobacco and other drugs.

“The very few investigations that have studied prenatal cannabis exposure and infant brain development have all involved women who are polysubstance drug users. No one has looked at marijuana use exclusively,” Natalia Kleinhans, associate professor of radiology at the University of Washington School of Medicine, said in a press release.  “This study will also involve periodic drug testing during pregnancy to verify in real time that moms aren’t using other drugs, rather than relying on the mother's self-report after the child is born."

The researchers will recruit 70 women who are 13 weeks pregnant or less at enrollment. Women will be split evenly into a control group and a cohort of women who use marijuana at least twice a week, mainly to tamper morning sickness.

Women in the test group will have to report their pot intake weekly, while researchers record percentages of tetrahydrocannabinol (THC) and cannabidiol (CBD), a non-active compound in pot.

At six months old, the babies will receive a formal evaluation to analyze their cognitive and social development, communication and motor skills, temperament and other behaviors. The infants will also undergo fMRI scans as they sleep, receiving an odor of phenyl-ethanol—a compound which actives brain regions associated with reward and addiction.

“Smell is one of the earliest developing senses, and it activates brain regions that have cannabinoid receptors and are involved in reward and addiction,” Kleinhans, said. “We will use fMRI to look at the integrity of the reward system that we think could be affected by marijuana – to see if there is a change.”