Not unsurprisingly - given the state of the economy - the relative number of search queries for they keywords "i feel depressed" have risen dramatically worldwide over the past year.

Interestingly, the UK, Australia, the US and Canada (in that particular order) lead the world in this particular query.

Much like the Google's Flu Trends tracker, seems like the opportunity is ripe here for pharma companies (among others) to track symptoms related to their diseases. 

Just a thought...