Living with depression isn't easy. Depression builds walls around people and between people. Someone living with depression may distance themselves from you. Be present. They may not want to talk, but you being there can help. Also know that when they need space, they need it. They aren't using it as some lame excuse to get out of your plans. There are thoughts that go through someone's mind when they are depressed. They may try to push you away for all kinds of reasons.
Don't Want To Inconvenience You
Depression takes a toll on people. It ruins lives. It's not an easy thing to go through, and a lot of people with depression try to distant themselves from their loved ones so they don't have to burden them with their problems.
Afraid Of Getting Close To Someone
Not only am I scared of getting hurt, I am scared of hurting everyone I love. Sometimes depression can cause someone to become irritable and lash out. For someone with depression, it is easier to distance themselves, rather than owe anyone an explanation.
It's Easier
It's easier to be alone, and not have to worry about anything or anyone. When you have depression, it's scary to open up to people. Not many people understand depression. Sometimes people are embarrassed to tell others their problems. It's easier to not burden people with the problems of depression. It's easier to not talk about it, especially when someone doesn't know anything about depression.
If you know someone who is suffering from depression, be there. Depression is not easy to go through, especially alone.