I question a lot if I am being lazy or it is the depression causing procrastination. Here's my thoughts on the difference:

• I see it as laziness if I put off a task because of the amount of effort involved and because there is something I find more fun/effortless to do.
• I see it as depression when I procrastinate on a task because my outlook is bleak and I don't think doing the task makes any difference.

Of course, I guess it could be both causing procrastination..