According to the National Multiple Sclerosis Society: "The question of whether marijuana  produced from the flowering top of the hemp plant, Cannabis sativa  should be used for symptom management in multiple sclerosis (MS) is a complex one. It is generally agreed that better therapies are needed for distressing symptoms of MS  including pain, tremor and spasticity. Still, there are uncertainties about the benefits of marijuana relative to its side effects. The fact that marijuana is an illegal drug in many states and by federal statute ... further complicates the issue.