As I've said before, I've been on both sides of the depression fence. I've suffered from clinical depression for almost forty years, although thankfully it's been treated successfully for the last twenty. And although I haven't had any family members with depression, I have had friends who were depressed and have been in relationships with men who have depression. 

I've written about what it feels like to be depressed. What does it look like from the other side? You probably know if you're dealing with someone who's depressed. It may be your spouse, parent, child, sibling, employee, roommate or romantic partner. Unless you have personal experience with depression, you're probably baffled, frustrated, and possibly hurt and angry. Even if you have suffered from depression, you still might be baffled. Your experience with depression, while probably fundamentally similar to this person's, is going to vary to some extent. 

Since knowledge can lead to understanding, I thought that my perspective on three depressive behaviors that can drive people around them crazy might be helpful.By the way, I'm not excusing their behavior or saying you should give them a free pass. You have the right to ask them to at least try to modify their behavior.

Lethargy

If you're dependent on the depressed person to share in the chores, child-rearing or household expenses, you may be in a bind. And you're wondering why they don't get off their lazy behind and do their part. When I was living with someone who was depressed, I came home at 6:00pm after battling a 1 1/2 hour commute to find the morning's dishes still in the sink, even though my partner got home at 4:30pm. He'd be lying on the couch watching tv and drinking beer. It wasn't that he was lazy - he was depressed and completely lacking in mental energy.

I know it's frustrating from your side, but here's what it's like from their side. You know when you have a really bad flu or virus and you can barely get out of bed? Just making a cup of tea seems like a monumental task. Well, believe it or not, that's what this person is probably dealing with, assuming, of course, that you've seen a change in their behavior and they're weren't always a lazy slob.

Withdrawal

When the depressed person withdraws emotionally and doesn't seem to have any interest in the rest of the family's lives, it's pretty painful. I've noticed, as someone with Multiple Sclerosis and kidney stones, that being in physical pain can have the same effect. Pain is like the kid in the class who's jumping up and down and saying, "Me, pick me!" It's really hard to focus on anything else. 
Depression is pain. If this is hard to believe, think of what we say about someone who's grieving. We say the person is "in pain" or "hurting." I've always been considered very stoic, but I the memory of the pain I went through with depression makes me shudder.
It might help to remember that the person is not deliberately withdrawing from you. It may feel that way, and I'm sure it hurts. But they are struggling to exist minute by minute, hour by hour and day by day. They don't really have much left to give.