Researchers are experimenting with a drug that could mean a paradigm shift in the treatment of mental illness. Dr Maryanne Demasi investigates whether a party drug could be the next big thing in treating depression. The drug of choice Ketamine, known on the street as Special K. Although its recreational use is illegal, it was originally developed as an aesthetic for soldiers during the Vietnam war. Researchers are now buzzing with the prospect of using Ketamine to treat mental illness.