He won't comply to your plans to watch a movie or have lunch together. All he'll want to do is mope around being a hopeless creature and stay like that until you fall asleep. These things happen. At such trying times, use your concern to get help, and motivate your partner in seeing his self worth; just let him be.
Genuinely ask your spouse what he requires at that moment. If it's possible, just give the thing he asks for. It could be anything from his favorite flavor of Sundae to seeing his best-loved television show. Create a list of things he likes, and offer one of the items whenever he feels depressed.
Read as much information as you can about depression. Ask your doctor about the stages involved in treatment, and get a thorough understanding of depression through whatever medium you can get. The more you know, the better you can cope with your depressed spouse.
You are entitled to spend your time pursuing meaningful interests in addition to deserving everyday niceties, like a clean surrounding in your house, timely meals and having a social life. Note that you may not be immune to depression yourself. So, balancing your personal pleasures with those of your spouse's will better equip you for managing the condition.