Constantly reassure them.
Let them know that whenever and wherever, you're always ready to hear them out. You don't have to be physically present all the time. Sometimes, even the thought of having someone is comforting enough. Just remain a friend them. During their rough times, the last thing they need in their lives is seeing their friends ditch them one by one. Make it clear to them that you’re here for them no matter what. Not just the ups, but most especially the downs.
Gauge them. Different people have different needs. Same goes with people going through depression. What works for other people won't necessarily work for your friend. There are those who react negatively to being coddled and questioned about their current state. There are those on the other hand who don't want to be left alone to their own loud thoughts. Try to figure out what your friend needs before you go off acting like a psychiatrist. It's important to be sensitive as to how they're doing.
First and foremost, you have to know that what they're going through is not easy. No matter how hard you try, you might never understand the extent of their hardships. It doesn't mean, however, that this should stop you from extending a helping hand. Conversations can be difficult. It's not easy for them to explain what's going on in their minds; it won't even be easy for them to open up to other people in the first place because they know that you won't understand. You might get frustrated, but that's because you don't know. So try to be patient. Don't give up on them. Others might have given up, but you shouldn't.
Don't play know-it-all.
Lend an ear when they need it. Offer a shoulder when they need to cry, but don't start giving unsolicited advice. Your opinion might matter, but it's not exactly going to help lift up their spirits from the depth of depression. It's highly probable that whatever you're going to tell them is something they've already heard over and over. Don't assume that they need someone to give them a lengthy sermon full of cliché advice. We know you mean well, but sometimes, all we need is someone to be there. We want a friend, not a doctor or a life coach.
Show them you care.
There are several ways to let them know you care. They weren't always depressed; surely they've experienced the ups at some point of their lives. Look back on those, and figure out what could bring their smiles back. Leave them small notes on random days. Give them a hug just because. There are so many little things that you can do for them that may seem so mundane and ordinary, but could actually be the only thing that pushes them to get up the next morning. Above all, share your time with them. There's nothing more that can show your genuine concern for them.
Let them know they're not alone.
It can get to the point that all your efforts are going nowhere. Let's face it; there's only so much you can do. You may have no personal experience whatsoever with depression, and you have absolutely no idea how to help your friend. You weren't trained or taught to deal with people who are going through what they're currently going through. There's even that chance that what we're doing isn't helping at all; it could actually be worsening it. With that, encourage them to see a professional (or at least call HOPELINE, a hotline for those experiencing emotional crisis or are in need of immediate assistance, at (02) 804-HOPE (4673), 0917 558 HOPE (4673), or 2919—a toll-free number for all GLOBE and TM subscribers). It's going to take a lot of convincing, but again, we don't want to aggravate the situation at hand. Remind them that they have so much more options available to them. They don't need to carry their burden alone.