To begin to try to understand the cause of the incident. Generally, the first rule of assistance during the depression is an opportunity to speak. Go to your favorite place to be adjusted in the confidential conversation, or buy a bottle of good wine. The main thing - to create a comfortable environment in which your friend would want to pour out his heart.
Perhaps one just quarreled with his half, and it is the third day does not want to pick up the phone when it rings. In this situation, you should not say, "Nonsense, found because of what the experience! ". You hihanki-hahanki, and for a man in love is akin to tragedy.
Try to send the mainstream conversation so that the person himself proposed solution to this problem. It is not necessary to spare others for too long. If you are within six months whine that casual acquaintance from the bar does not respond to his advances, it is logical and appropriate to say something like: "Gather, rag, as you can complain ?! ". Resentment people really might want to show that he was not a rag and start acting.
Of course, there are reasons to which it is impossible to come up with solutions, for example, if your friend is dead someone from the family. In such situations, the best thing you can do - is to be there and help as much.
And remember that depression - is not just a bad mood, and a serious illness in which the lethal outcome. If your friend is depressed for several months, if he became distracted, nothing pleases him, and he occasionally speaks about the worthlessness of life, gently persuade him to see a specialist. This way you can save his life.