With the increased legalization of recreational cannabis, as many as 1 in 5 pregnant women in the U.S. are now using the drug to help with morning sickness, lower back pain or anxiety.
Evidence has been growing, however, to suggest that tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, poses risks to the developing fetus by impacting brain development. Now a new study finds that this could increase the risk of addiction to opioids later in life. The preclinical animal study, led by researchers at the University of Maryland School of Medicine, was published in the journal Science Advances .
It found that prenatal exposure to THC causes a rewiring of the fetal brain. THC caused certain brain cells, called dopamine neurons, to respond in a hyperactive way, causing a heightened increase in dopamine release. This was accompanied by heightened neuronal responsiveness to cues associated with rewards like a light turning on to indicate that food or an opioid drug was available.
Doctors are contending with an explosion of cannabis use, and the THC content has quadrupled from what it was a generation ago. It demonstrates the enduring consequences that prenatal cannabis exposure exerts on the brain's reward system, which ultimately results in a neurobiological vulnerability to opioid drugs." Joseph Cheer, PhD, study corresponding author, Professor of Neurobiology and Psychiatry at the University of Maryland School of Medicine The American College of Obstetricians.