As the legalization of recreational cannabis continues to rise across the United States, studies estimate that nearly 20% of pregnant women are now using the drug to alleviate symptoms such as morning sickness, lower back pain, or anxiety. However, researchers are increasingly concerned about the potential risks associated with tetrahydrocannabinol (THC), the principal psychoactive component in cannabis, particularly its detrimental effects on fetal brain development. A groundbreaking new study suggests that prenatal exposure to THC may significantly heighten the risk of opioid addiction in later life stages.
The preclinical study was conducted by a dedicated team at the University of Maryland School of Medicine and has been published in the esteemed journal Science Advances. The research demonstrates that prenatal THC exposure leads to a reconfiguration of the fetal brain’s architecture. This exposure resulted in a hyperactive response from dopamine neurons—brain cells crucial for processing rewards—thereby amplifying dopamine release. Consequently, heightened neuronal responsiveness to reward-associated cues, such as a light signaling the presence of food or opioid drugs, was observed.
Medical professionals are facing an unprecedented surge in cannabis use, where the THC concentration has skyrocketed fourfold compared to previous generations. This underscores the lasting impacts that prenatal cannabis exposure has on the brain’s reward system, ultimately rendering individuals more susceptible to opioid addiction.”
Joseph Cheer, PhD, corresponding author, Professor of Neurobiology and Psychiatry at the University of Maryland School of Medicine
The American College of Obstetricians and Gynecologists strongly advises healthcare providers to educate their patients about the potential risks associated with continued cannabis use during pregnancy. Dr. Cheer and his research team are in a race against time to uncover detailed insights about THC’s effects on developing fetuses, aiming to enhance doctor-patient consultations regarding the ramifications of cannabis consumption.
This study illustrates that male animal subjects exposed to THC in utero exhibit a heightened release of the “reward-seeking” neurotransmitter dopamine when subsequently exposed to opioid drugs during adolescence compared to their unexposed counterparts.
Upon reaching early adulthood, THC-exposed animals demonstrated a notable increase in opioid-seeking behaviors and were more inclined to relapse when encountering opioid-related environmental cues, unlike those that had not been exposed to THC in utero. Furthermore, they exhibited persistent addiction-like behaviors, amplifying the concerns regarding prenatal cannabis exposure.
“These findings bolster the hypothesis that a sensitized ‘wanting’ system within the brain emerges following THC exposure during prenatal development,” remarked Dr. Cheer. “Interestingly, our results show that this pronounced opioid-seeking tendency is significantly more prevalent in males compared to females, and our ongoing research aims to explore the underlying reasons for this discrepancy.”
Dr. Cheer, alongside his colleague Mary Kay Lobo, PhD, Professor of Neurobiology at UMSOM, co-directs the Center for Substance Use in Pregnancy, located within UMSOM’s Kahlert Institute for Addiction Medicine. Together with a collaborative team of researchers, they are investigating the long-lasting effects of both drug and alcohol exposure during gestation.
“A comprehensive understanding of the enduring effects of THC exposure in the womb is crucial, as is determining whether we can mitigate some of the harmful consequences through advanced CRISPR-based gene therapies or repurposed medications,” stated Mark T. Gladwin, MD, Dean of UMSOM and vice president for medical affairs at the University of Maryland, Baltimore. “It is essential that we offer improved guidance to pregnant patients, many of whom opt for cannabis as a perceived safer alternative to traditional anti-anxiety medications.”
The National Institute on Drug Abuse funded the study (Grant: R01 DA022340) (Grant: K99 DA060209). The paper’s first author is Miguel A. Lujan, PhD, a research associate in Neurobiology.
Source:
University of Maryland School of Medicine
Journal reference:
Luján, M. Á., et al. (2024). Dynamic overrepresentation of accumbal cues in food- and opioid-seeking rats after prenatal THC exposure. Science Advances. doi.org/10.1126/sciadv.adq5652.
What are the potential long-term effects of prenatal THC exposure on a child’s brain development?
**Interview with Dr. Joseph Cheer: Impacts of Prenatal THC Exposure on Future Opioid Addiction**
**Editor:** Welcome, Dr. Cheer. Thank you for joining us to discuss your groundbreaking research on the effects of prenatal THC exposure. To start, could you summarize the key findings of your study?
**Dr. Cheer:** Thank you for having me. Our study, published in *Science Advances*, found that prenatal exposure to THC can significantly alter the brain’s architecture in developing fetuses, leading to long-term effects on reward processing. In particular, we observed an intensified response from dopamine neurons in males, which heightens their susceptibility to opioid addiction later in life.
**Editor:** That’s quite alarming. Considering nearly 20% of pregnant women are using cannabis, what specific risks should healthcare providers communicate to their patients?
**Dr. Cheer:** Absolutely. Healthcare providers need to emphasize that while some may use cannabis to alleviate issues like morning sickness or anxiety, the potential risks—especially concerning fetal brain development—may far outweigh short-term benefits. THC can rewire the brain’s reward system, increasing the likelihood of addiction to substances like opioids.
**Editor:** You mentioned that your research highlights a gender difference in opioid-seeking behavior among subjects. Can you elaborate on that?
**Dr. Cheer:** Yes, we found that male subjects exhibited much stronger opioid-seeking behaviors compared to females after THC exposure in utero. This raises important questions about biological differences and susceptibility to addiction, which we are actively investigating in ongoing research.
**Editor:** With the increasing legalization of cannabis and higher THC concentrations available, how should this influence public policy and medical advice?
**Dr. Cheer:** It’s crucial for public policy to adapt to these findings. We advocate for education and clearer guidelines around cannabis use during pregnancy. The American College of Obstetricians and Gynecologists is already urging healthcare providers to counsel patients about the risks. Comprehensive understanding and communication about potential consequences are essential in guiding pregnant women’s decisions.
**Editor:** What do you see as the next steps in your research?
**Dr. Cheer:** We are focused on understanding the mechanisms behind the gender differences we observed and the long-term effects of THC exposure. Additionally, we aim to conduct studies that further explore how these changes manifest in behavior and addiction vulnerability across different developmental stages.
**Editor:** Thank you, Dr. Cheer, for sharing these important insights. It’s clear that further research and education are vital as we navigate the landscape of cannabis use and its implications for maternal and fetal health.
**Dr. Cheer:** Thank you for bringing attention to this critical issue. Education and awareness are key to ensuring healthier outcomes for future generations.