Balash Y, et al. - Here, the researchers described the outcomes of a standardized interview study that retrospectively evaluated the effects of medical cannabis (MC) on symptoms of Parkinson's disease (PD) and its adverse effects in patients treated for at least 3 months. In the initial stages of treatment, medical cannabis was found to improve symptoms of PD and did not cause major adverse effects in this pilot, 2-center, retrospective survey. The extent of use and the reported effects supported further development of safer and more effective drugs derived from Cannabis sativa.