What Missionaries Ought to Know about Depression by Ronald L. Koteskey
Christians: Take Depression Seriously by Tony Campolo: “With prayer, ‘all things are possible’, but sometimes depression requires additional action.”
How to Help When Your Spouse Is Depressed by Carolyn MacInnes: “Here’s how you can help your loved one out of the darkness of depression.”
The Mind website has great resources concerning mental health, including depression.