Medical marijuana users claim the drug helps relieve pain and suppress nausea, the two main reasons it's often used to relieve the side effects of chemotherapy. In 2010, researchers at Harvard Medical School suggested that that some of the drug's benefits may actually be from reduced anxiety, which would improve the smoker's mood and act as a sedative in low doses. Beware, though, higher doses may increase anxiety and make you paranoid.- Business Insider - Meg Sanders pictured