The short answer is no.
A group of physicians of Stanford University School performed a systematic review of studies on the impact of cannabis use in brain development in young people with attention deficit hyperactivity disorder (ADHD). They examined eleven studies and compared outcomes for individuals with ADHD who used cannabis against those with ADHD who did not. These studies used neuroimaging techniques, including MRI, to identify regions of activation and morphological differences in the brain. No study identified any additive or ADHD × cannabis use interaction on neuropsychological tasks of executive function.
The study concluded that the existing limited, potentially underpowered evidence does not support the hypothesis that cannabis use harms brain development in youth with ADHD. Larger and longer-term studies are needed to better inform clinicians and patients as to the impacts of cannabis use in youth with ADHD.
Reference:
Cawkwell, P. B., Hong, D. S. & Leikauf, J. E. Neurodevelopmental Effects of Cannabis Use in Adolescents and Emerging Adults with ADHD: A Systematic Review. Harvard Review of Psychiatry Publish Ahead of Print, (2021). https://pubmed.ncbi.nlm.nih.gov/34138796/
