It's long been believed that smoking pot helps MS patients, and a study published as recently as May provided yet another clinical trial as evidence of marijuana's impact on multiple sclerosis patients with muscle spasticity. Even though the drug has been known to cause dizziness and fatigue in some users, most MS patients report marijuana not only helps ease the pain in their arms and legs when they painfully contract, but also helps them just feel good. How many prescription drugs can say their side effects include happiness?