The best thing for me to hear was just "I'm sorry you're going through that. I don't know what it's like, but I'm here for you and if there's something I can do to help, please tell me."

Since you don't know what it's like, trying to pretend you do, or trying to minimize the symptoms will come across the wrong way. However, being honest and open and willing to just sit and listen IS helpful. It might be hard to have to just "sit back and watch" him go through phases, but really, there's nothing you can actually do to get him through a depression.

If he wants your company, or maybe wants something like touch or peace and quiet or a movie or balloons or something like that - let him tell you what would be helpful. I know if my husband brought me flowers on some days that would rock - on other days it would send me off the deep end because I would be completely unable to be happy about them and that would make me feel worse.

I know it's hard to watch, but just be willing to support when he asks for it and he'll be thankful in the end.