I've almost always experienced depression from an inside perspective. Apart from, you know debilitating self-loathing, another disadvantage this gives me is that I often have a hard time seeing what depression looks like from an outside perspective.
Still, the great thing about being human is you can put yourself (to an extent) in another person's shoes with some mental effort. Most of us don't do this as often as we should but I don't think anyone would say that trying to grasp another person's perspective is a bad thing.
As a depressive, trying to think of how others perceive me can also help me understand challenges those who don't suffer from depression have when they look at those who do.
One common question I think a lot of people who want to help a loved one with depression face is -What do I say to them?
This is a tough item to advise on even for someone who has regular struggles with depression. Many times, we depressives don't always know what it is we want or need to hear. When I'm in a depressed state I sometimes don't have the mental clarity to know what is I need to hear or need to do to feel better. All that I can really feel and comprehend is misery.
Depression also makes your entire perspective on life skewed. Everything gets filtered and twisted through a negative voice that makes even the most well intended advice come off in a critical light. For me this is especially true with advice such as 'Oh, maybe you should exercise more.' or 'Try and list all the positive things in your life.' While is this very well meaning advice and might help some people, a depressed mind will often process this as 'You see, this is something you could easily fix. You don't have any excuse for why you feel this way. You suck.'
Depression is very clever like that.
Lastly, knowing what to say to a depressed person is hard to know because everyone experiences it differently. Although depression can generally be defined with terms like 'deep and ongoing sadness' and 'crippling despair' people experience it differently from one another. What triggers episodes in one person might not be a big deal for another person. As such, advice, comforting words or activities that might help one person won't necessarily be of benefit to another. I've known some people who use yoga to treat depression. For some that doesn't work mental exercises do.
With all of that said though, and keeping in mind that what works for me might not work for you, I do think there's one message that depressed people need to hear, often multiple times. That is:
I think often we, (people) try and give advice to depressed people first without really making it clear first that we recognize the person's pain and still accept them. You may not necessarily understand it but you see that they are struggling and to be in that struggle is okay.
From my own experience and based on what I've shared what other depressives, we very often know that we can take actions to make our lives a little easier. Often we're already in therapy and browsing tons of articles to try and understand and cope with our condition better.
When depressives get into a mood, we often know that our feelings are ridiculous in many cases. I know logically that the negative criticism I'm bombarded with is often not accurate. However, it's so powerful that it overwhelms me.
What we often lack in those dark times is not ways to feel better or a sense that it's okay that we feel this way. That our feelings or lack thereof are real and that the people who matter to us see this and value us nonetheless.