If you are the friend of a depressed individual, especially one who has opened up about having depression, there a number of things you can do to help.
First and foremost, you should encourage your friend to seek professional help, such as therapy or a variety of on-campus resources (though keep in mind that the reactions may not always be as helpful as desired). If you're considering an intervention, be aware of the risks and make sure to have a proper plan of action.
However, there are a number of daily actions that can help your depressed friend. Be a good listener and offer words of encouragement to show that you are supportive, not critical or judgmental. If your friend is seeking help from professionals, you can aid them in that search and offer to accompany them to appointments. Be as patient and understanding as possible, and don't ignore any comments they make, especially if they involve suicide or self-harming thoughts. Invite your friend to outdoor outings or other activities. Be positive in reminding your friend that depression does, can, and will lift. Understand and learn all that you can about depression. Help them make a plan to defeat their depression by identifying triggers as well as things that induce positive emotions. Help them with daily tasks like running errands or doing the dishes. Spend "normal" time together to show that your friendship has not changed. Overall, in an easy to remember format, you should: communicate care and concern; ask, assess, and affirm; reach for resources and refer; and engage, explain, and eliminate danger. And, above all, be there.
Be the friend.