Using cannabis while pregnant predisposes the baby's brain to opiate addiction

The exhibition in utero Cannabis predisposes adolescents and young men to drug use by a mechanism that an American study has just demonstrated in rats. In a person who has become dependent on a drug such as morphine, the desire to consume the product is irrepressible. The slightest indication linked to this consumption triggers a search for the drug to alleviate the feeling of withdrawal.

It is this impulsivity that was found in rats exposed in utero to THC, the psychoactive compound in cannabis. The animals responded much longer to cues of food reward and showed overactivation of motivational neurons, the ones that release dopamine in the brain. This behavior did not result from an increased preference for the food offered in the exposed rats in utero.

Male vulnerability to addiction

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These animals exhibited the same behavior when they were accustomed to consuming a drug such as Fentanyl, an illegal analogue of morphine widely used in the United States. Rodents were again much more motivated to administer the drug and to ask for it at the slightest indication of a possibility of consuming it, even more strongly than for a food reward. This consequence on the behavior of exposure to THC in utero only concerned male rats, specify the researchers from the School of Medicine of the University of Baltimore (United States). A vulnerability linked to sex already observed in epidemiological studies.

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In the United States, a liberalization of cannabis consumption

For the authors of the study published in the journal Science Advances, this difference between the sexes remains unexplained but confirms the relevance of their animal model to better understand how exposure to THC in utero affects human brain development. In the United States, the liberalization of cannabis use has been accompanied by a sharp increase in the number of pregnant women who use the drug in the hope of relieving or avoiding nausea and vomiting. This use, encouraged by misleading advertising, risks making a generation of young men much more impulsive and dependent on drugs, including opiates.