“Some of kratom’s alkaloids bind to opioid receptors in the brain, making it an opioid agonist, and it is now being sold in the West and used to treat pain, depression, anxiety, and opiate withdrawal. Sold in smoke shops, herbal supplement emporia, and on the Internet, it is now apparently being lumped in with synthetic cannabinoids and the ‘bath salts’ drugs by treatment professionals, law enforcement, and others who make a habit of searching for scary new drugs.”
http://stopthedrugwar.org/chronicle/2012/aug/08/now_theyre_trying_ban_kratom_fea