In the last few years, calls for marijuana to be researched as a medical therapy have increased. It may be time for us to consider the same for psychedelic drugs. Two general classes of such drugs exist, and they include LSD, psilocybin, mescaline and ecstasy (MDMA). All are illegal in the United States, [and can] cause harm. The best-known adverse event is persistent flashbacks, though these are believed to be rare. More common are symptoms like increased heart rate and blood pressure, anxiety and panic. Some people have pointed to ... positive effects. People with life-threatening illnesses can also suffer from anxiety, which is hard to treat. In 2014, a small randomized controlled trial was published that examined if LSD could be used to improve this anxiety. Anxiety was significantly reduced in the intervention group for up to a year. More common are studies of the use of psychedelics to treat abuse or addiction to other substances. [One study] exploring LSD's potential to treat alcoholism [found that] alcohol use and misuse were significantly reduced in the LSD group for six months. Similar studies using psilocybin have also shown promising results. Researchers [have also] examined the potential for MDMA in the treatment of chronic and treatment-resistant post-traumatic stress disorder. At two months after therapy, more than 80 percent of those in the treatment group saw a clinical improvement versus only 25 percent of those in the placebo group. The beneficial effects lasted for at least four years, even with no further treatment.