The drug ketamine is probably most often associated with its use as an anesthetic in veterinary medicine and its recreational abuse under the name "special K." However, scientists at Yale University have been testing its effects at treating depression for the last decade and have just come to a breakthrough surrounding its potential therapeutic uses. As published in the journal Science, Yale's researchers have found that ketamine can help regenerate synaptic connections between brain cells that have been damaged by depression. The drug works in a completely different way from other, more traditional anti-depressants — while standard drugs may take weeks or months to fully take effect, small doses of ketamine can offer near-immediate therapeutic relief.

Of course, there are some downsides — the improved symptoms only last about seven to ten days, and of course the potential for misuse of the drug is an ever-present concern. To that end, scientists are attempting to develop drugs that treat depression in the same fashion as ketamine, but thus far the quick-acting effect of the drug has been difficult to duplicate. Unfortunately, that rapid response is the real prize the scientists are after — Ronald Duman of Yale University said, "The rapid therapeutic response of ketamine in treatment-resistant patients is the biggest breakthrough in depression research in a half century."