and 2016. this drew strong protests among those using kratom to deal with chronic pain or wean themselves off opioids or alcohol. a group of 51 members of the u.s. house of representatives and a group of nine senators each sent letters to acting dea administrator chuck rosenberg protesting the listing and around 140,000 people signed an online white house petition protesting it. the dea noted the responses but said that it intended to go forward with the listing; a spokesman said: "we can't rely upon public opinion and anecdotal evidence. we have to rely upon science." in october 2016, the dea withdrew its notice of intent while inviting public comments over a review period ending on december 1, 2016. as of july 2016, alabama, arkansas, indiana, vermont, and wisconsin had made kratom illegal, and the us army had forbidden soldiers from using it. between february 2014 and july 2016, u.s. law-enforcement authorities "encountered 55 tons of kratom," or roughly "50 million individual doses," according to the international narcotics control board. public response the fda's arguments for the federal prohibition of kratom have drawn both criticism and support. fda commissioner gottlieb responded to criticism in 2018 by stating that “the fda has done an exhaustive review of adverse event reports, clinical literature and other sources of information related to kratom." however, in 2021, former acting commissioner of food and drugs brett giroir claimed that the fda's recommendation to schedule kratom was rejected because of "embarrassingly poor evidence data." the fda's position on kratom has also been criticized by the american kratom association and researchers including walter prozialeck. former commissioner gottlieb continued to defend the agency's position in 2021, stating that he was convinced that kratom was fueling the u.s. opioid epidemic, though gottlieb's partiality has been called into question as he has since gone on to become a member of the board of directors of pfizer inc., a company that has been heavily criticized for its sale and marketing of opioid drugs. research kratom is under preliminary research for its possible antipsychotic and antidepressant properties. survey studies found that some people use kratom as a self-treatment strategy for conditions such as opioid use disorder, acute pain, chronic pain, and various mental health conditions, including anxiety, adhd and depression. kratom is also being studied in order to design novel drugs for treating pain, opioid use disorder, and alcohol use disorder. further clinical research is necessary to corroborate anecdotal reports of kratom as an effective treatment for chronic pain, and to determine whether it is a safe or effective treatment for illness.