Are you still happy?

My office mate said that he is having attacks of depression (?) lately. He easily gets irritated and sensitive even to very small matters. He said that he becomes like this when he is not happy anymore with the things around him. Like our job? When you are doing the same thing for almost ten years then maybe there is a reason of being unhappy already. He is now thinking of resigning and look for another work. I wish I could afford it too. Am I not happy also? Not really but there are many other factors why I would like to take a new road.