A new study led by Prof. Ilan Matok and Hely Bassalov PharmD from the Department of Clinical Pharmacy at Hebrew University’s School of Pharmacy, in collaboration with Prof. Omer Bonne and Dr. Noa Yakirevich-Amir from the Department of Psychiatry at Hadassah Medical Center, reveals nuanced insights into the neuropsychiatric risks of prenatal cannabis exposure. The research identifies a slight increase in the risk of attention-deficit/hyperactivity disorder (ADHD) and a greater likelihood of cannabis use in offspring exposed to cannabis in utero. However, it found no significant associations with autism spectrum disorder (ASD), psychotic symptoms, anxiety, or depression.
The study, a comprehensive systematic review and meta-analysis, analyzed data from over 500,000 participants across observational studies. It focused on the effects of Δ9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, which can cross the placenta and potentially impact fetal brain development.
Key findings include:
A slight increase in ADHD risk in children exposed to cannabis during pregnancy.
A heightened vulnerability to cannabis use in these children.
No significant association with ASD, psychotic symptoms, anxiety, or depression.
Prof. Matok cautions that while these findings offer important insights, they do not confirm the safety of cannabis use during pregnancy. He emphasizes the need for continued research, noting that most studies in this review were conducted from the 1980s to the early 2000s, a period when cannabis had lower THC concentrations compared to contemporary products. This historical context may result in an underestimation of the impact of current prenatal cannabis exposure.
The study’s methodology included an analysis of 18 observational studies, with 17 contributing to the quantitative analysis. These studies, which collectively involved 534,445 participants, compared neuropsychiatric outcomes in offspring exposed to cannabis prenatally with those unexposed. The review covered various conditions, including ADHD, ASD, anxiety, depression, psychotic disorders, and substance use, reflecting data from multiple countries up to January 2024.
Prof. Matok underscores the importance of exercising caution and staying informed about the potential risks associated with cannabis use during pregnancy. As legal regulations around cannabis continue to evolve, ongoing research will be crucial in shaping public health recommendations and safeguarding future generations.
