6. Keep in mind that depression is "contagious." That may sound silly, but it's very common for family members of someone with depression to develop it themselves. Keep an eye out for any signs of depression in you or other family members, and hotfoot it to a doctor if it becomes apparent that treatment is called for.

7. Find a therapist - for you. Your partner should definitely be in therapy, and you might want to go to couples counseling jointly, but you need someone objective who is also on your side. The therapist can help you develop coping strategies, and also help you determine the answer to the question in the next tip.

8. Decide what your "line in the sand" is. Are you staying with your partner no matter what? What if your partner refuses to get help? Bear in mind that this decision is for you alone. Using it as a threat or ultimatum with the depressed person ("If you don't get treatment I'm leaving") is not necessarily going to do anything.

9. Take care of yourself physically. You need to eat well and exercise to get rid of stress.

10. Read one of the books listed below. They contain practical strategies for maintaining your relationship and your sanity when you're involved with someone who's depressed.

Books

When Someone You Love is Depressed: How to Help Your Loved One Without Losing Yourself by Laura Epstein Rosen, Ph.D. and Xavier Francisco Amador, Ph.D.
How to Live With a Mentally Ill Person: A Handbook of Day-to-Day Strategies by Christine Adamec
The Burden of Sympathy: How Families Cope with Mental Illness by David Karp