From the Research
Pregnant women should be advised to avoid cannabis use completely during pregnancy due to the potential link between prenatal cannabis exposure and increased risk of ADHD in children. The most recent and highest quality study, 1, a scoping review published in 2023, found that the current evidence does not support the use of cannabis for the treatment of Attention Deficit Hyperactivity Disorder (ADHD), and that cannabis use may worsen or have no effect on ADHD symptoms. Although the evidence is not yet definitive, children exposed to cannabis in utero may have a moderately higher likelihood of developing attention problems and hyperactivity, with the association appearing dose-dependent and heavier maternal cannabis use potentially carrying greater risk.
Key Points
- The biological mechanism likely involves THC (tetrahydrocannabinol) crossing the placental barrier and affecting the developing endocannabinoid system in the fetal brain, which plays a crucial role in neurodevelopment and the formation of neural circuits involved in attention and executive function.
- Healthcare providers should screen for cannabis use during prenatal visits and provide support for cessation.
- Women requiring treatment for conditions like nausea or anxiety during pregnancy should discuss alternative, evidence-based treatments with their healthcare provider rather than self-medicating with cannabis.
- The recommendation to avoid cannabis use during pregnancy applies to all forms of cannabis, including smoking, edibles, oils, and vaping products.
Considerations
- The study 2 found that 35% of pregnant women reported currently using cannabis at the time of diagnosis of pregnancy, and 34% of those women continued to use it, highlighting the need for clear messaging on the effects of cannabis use during pregnancy.
- The study 3 reported improvements in ADHD symptoms in three cases where patients used cannabis, but this was not a controlled study and the results should be interpreted with caution.
- The studies 4 and 5 provide information on the safety of over-the-counter medications and SSRI antidepressant use during pregnancy, but do not directly address the link between prenatal cannabis exposure and ADHD.