There have been a lot of inventions.  Many are good.  But what if you could erase one?  Use your power wisely.  And no, depression is unfortunately not an invention.  It is, however, an insidious force that can not only sap your energy to do anything, but it can transform into things like anxiety.  The more a wound festers, the harder it is to treat; this is true of both physical wounds as well as emotional ones.