What impact does cannabis have on an unborn child? “We found offspring exposed to prenatal cannabis had an increasing risk of ADHD symptoms and/or disorders and ASD compared to non-exposed,” the research team wrote. The team noted that exactly how prenatal cannabis exposure leads to an increased risk of ADHD symptoms or autism isn’t fully understood. Animal-based studies suggest that prenatal cannabis exposure directly alters neurodevelopment, especially in the prefrontal cortex, which is associated with cognitive impairment and emotion regulation. In human studies, researchers believe that delta-9-tetrahydrocannabinol (THC), the psychoactive component in cannabis, can cross the placenta and fetal blood-brain barrier. When this happens, it can disrupt fetal neurodevelopment, mirroring the results of the rodent studies. “Furthermore, neurodevelopmental data in humans suggested that prenatal exposure to THC may lead to subtle, persistent alterations in behavioural, cognition and psychological well-being,” the research team wrote. Other research has pointed to the impact of cannabis exposure during the first trimester, the researchers added. Many heritable formations occur during the first trimester, and it is during this period, researchers believe, that children have an increased risk of developing ADHD symptoms like impulsivity, inattention, and hyperactivity. In 2011, the number of children diagnosed with ADHD peaked at 6.4 million; between 2016 and 2019, the number remained relatively stable at 6 million. Boys are more likely than girls to be diagnosed. Black children and white children (12 percent and 10 percent, respectively) are more often diagnosed with ADHD than Hispanic or Asian children (8 percent and 3 percent, respectively). Many children with ADHD also have coexisting disorders, such as behavioral or conduct problems (52 percent), anxiety (33 percent), depression (17 percent), autism spectrum disorder (14 percent), or Tourette syndrome (1 percent).