Be compassionate and listen, and remember to set boundaries for how much you are able to handle, it's not your job to make a depressed person feel better but you can offer an ear and kind words. If they want to find a therapist or psychiatrist you can offer to help with the search since depression usually causes brain fog and complete lack of motivation. That's my take on it as a person who has been inconsolably depressed before. The person with depression has to be trying to help themselves too. I hope that helps!