Those who get married traditionally take the vow to care for one another "in sickness and health." It's difficult enough to do that when your partner battles physical illness, but mental illness is a whole 'nother story. For those whose relationships are affected by clinical depression, it can be a struggle to stay together and keep the unaffected partner healthy, too. Depression is characterized not only by feelings of sadness, lethargy and despair, but also anger, withdrawal and disinterest. The latter qualities can take a toll on a relationship, making the caretaking spouse feel unloved and unappreciated. It's important to understand that people with depression are not themselves. Recovery isn't fast. Depression is recurrent, and the affected partner can't just will the effects away. It's important to keep in mind that depression is an illness, and it can make both parties lose the will to work things out in the relationship. The person suffering from depression can lose interest in pretty much everything that makes a relationship successful – sex, shared activities, friends, family and more.