Medical marijuana is legal in 29 states and Washington DC. A new review of medical research, "Medical Cannabinoids in Children and Adolescents: A Systematic Review," published in the November 2017 issue of Pediatrics (published online October 23), found evidence that marijuana can be an effective treatment for chemotherapy-induced nausea and vomiting, with increasing evidence of a benefit for epilepsy. Researchers found 22 relevant studies on the medical benefits of cannabinoids for young patients, including six studies on the impact it has on chemotherapy-induced nausea and vomiting and 11 studies on epilepsy.

They found insufficient evidence to support use of cannabinoids to treat spasticity, neuropathic pain, posttraumatic stress disorder, or Tourette syndrome. Researchers concluded that while these findings are encouraging, more research is needed to evaluate the potential role of medical cannabinoids in children and adolescents, especially given increasing accessibility from state legalization, and potential psychiatric and neurocognitive adverse effects identified from studies of recreational cannabis use.