MDMA, once used as a therapeutic counseling tool, was banned in May 1985 under schedule one of the United States drug laws, triggered by the report that it had caused brain damage in rats. The British government imposed harsh penalties on users and distributors of this drug in 1977. The appearance of the drug varies depending on purity. Effects can last several hours and symptoms include dilated pupils, brief nausea, sweating, dry mouth and throat, some rise in blood pressure and heart rate, and loss of appetite. No overdose deaths from MDMA have been recorded. The drug appears to stimulate empathy between users, but there is no proof that Ecstasy is an aphrodisiac. Some long-term users have reported increased susceptibility to minor ailments such as cold, flu, and sore throats. Potentially greater problems may arise due to related chemicals present as impurities in MDMA or sold instead of the drug.