A recent study from the University of Maryland School of Medicine has revealed that prenatal exposure to tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, may increase the risk of opioid addiction in later life. As recreational cannabis use becomes more widespread, with approximately 1 in 5 pregnant women in the U.S. using it to alleviate symptoms such as morning sickness, lower back pain, or anxiety, concerns about its impact on fetal brain development have intensified.
Published in the journal Science Advances, the preclinical animal study indicates that THC exposure during pregnancy alters the development of the fetal brain, particularly affecting dopamine neurons. Researchers found that THC caused these neurons to become hyperactive, leading to an increased release of dopamine and heightened sensitivity to reward-related cues, such as signals indicating the availability of food or opioids.
Joseph Cheer, PhD, the study’s lead author and a professor of neurobiology and psychiatry at the University of Maryland, emphasized the long-term implications of prenatal cannabis exposure. “The THC content in cannabis has quadrupled over the past generation, and this study underscores the lasting effects that prenatal exposure can have on the brain’s reward system, resulting in a neurobiological vulnerability to opioid drugs,” he stated.
The American College of Obstetricians and Gynecologists advises healthcare providers to discuss the potential adverse effects of cannabis use during pregnancy with their patients. Dr. Cheer and his team are actively researching the health consequences of THC exposure to better inform medical guidance.
In the study, the researchers observed that male animals exposed to a moderate dose of THC—equivalent to a mother smoking one to two joints daily—developed significant changes in their reward system. These changes resulted in a pronounced inclination toward opioid-seeking behaviors. THC-exposed animals demonstrated a much greater motivation to obtain opioids compared to those not exposed to the drug in utero. Furthermore, as these animals reached early adulthood, they exhibited increased opioid-seeking behavior and were more prone to relapse when exposed to opioid-related environmental cues.
In subsequent experiments, the researchers implanted sensors in the animals’ brains to measure dopamine release, which was found to be heightened in those displaying strong addiction-like behaviors. “These findings support the hypothesis of a hypersensitized ‘wanting’ system that develops in the brain after prenatal THC exposure,” Dr. Cheer noted. He also pointed out that this opioid-seeking behavior was significantly more pronounced in males than in females, prompting further investigation into the reasons behind this disparity.
Dr. Cheer’s previous research, published in Nature Neuroscience, indicated that prenatal THC exposure leads to hyperactivity in dopamine neurons, which could increase the risk of psychiatric disorders, including schizophrenia. His findings have been independently validated by multiple laboratories worldwide.
Alongside his colleague Mary Kay Lobo, PhD, Professor of Neurobiology, Dr. Cheer co-directs the Center for Substance Use in Pregnancy at the University of Maryland’s Kahlert Institute for Addiction Medicine. They are collaborating with a research team to explore the long-term effects of drug and alcohol exposure during pregnancy.
“We need to fully understand the lasting impacts of THC exposure in the womb and investigate whether some of these harmful effects can be reversed through CRISPR-based gene therapies or repurposed medications,” said Mark T. Gladwin, MD, Dean of UMSOM. “Additionally, we must provide better guidance to pregnant patients, many of whom believe cannabis is a safer alternative to traditional anti-anxiety medications.”
Related Topics:
-
Pregnancy Antiepileptic Drugs Are Associated With Neurodevelopmental Risks In Children
-
Discrimination May Lead To Postpartum Weight Maintenance In Black Women
