From the Daily Telegraph/National Post: A biological test for clinical depression has been developed by scientists in a breakthrough that researchers say will enable it to be identified and treated at an earlier stage. Academics at Cambridge University have established a link with excess levels of the hormone cortisol.
It means that for the first time, doctors could definitively identify the illness by a simple blood test. It also marks the first time that scientists have established that depression could be caused by a chemical imbalance.