How would you all handle a relationship if your partner has depression?

I would encourage them to seek help. If they refuse you can not make
someone want help.

i plead the 5th

It's hard being in a relationship with a depressed person that does not
believe that they need help. All that you can do is offer your
support.Be there but don't loose yourself in this person's illness.

Shagna is right, the best thing would be for them to talk to a
professional. The best thing you can do for a partner in that situation
is to encourage them to talk to someone in a professional capacity, and
to be there for them all the way through the process.

Let them know that their mental well-being is extremely important to
you, and that you want them to get better and feel better, and that you
will be there for them. It helps to be a good listener, and to develop
a lot of patience.

Encourage them to talk about their feelings, and reassure them that
they're not crazy and you're not going to turn your back on them.
Sometimes it helps if they know they're loved and that you're willing to
take the time to help them and stand by them through the problem.

Depression stems from anger. If a person who is in a
long-term-relationship [years] is depressed/angry, there is a reasonably
good chance that something is dysfuncutional in the relationship.

Maybe one is realizing they're not fully self-realized. Maybe one feels
put-upon by the other. Maybe one feels un-appreciated. Maybe one feels
they're not being heard.

There's no magic "professional counselor" to magically cure it. There
are no drugs to magically cure it. Sure a good counselor will help you
recognize the core issue, but they wont "fix" them. The core issues will
still need resolution by your own efforts. Same with the medications,
they can help alleviate some of the intensity, but, only as a stepping
stone to fixing the core issues.

If your partner is "depressed" and you really want to help, you really
need to be willing to hear and change things about yourself. Including
the possibility of letting them go.

shagna took the answer out of my fingers!!