So- I eat a fair amount of chocolate - not loads of it- but I always have some around the house and have it a few times a week in managable quantities---
http://online.wsj.com/article/SB10001424052748703465204575208380988174438.html?mod=dist_smartbrief I'm also usually quite happy- things happen- this is true and once in a while life can bring me down- but I don't think it has anything to with the chocolate. Hell the most depressed I think I've been in the last 5 years was during my hormonal issues recently and now that I'm back on track- that seems to have dissipated.
So- I think when people are depressed they eat more chocolate becuase it lifts their spirits- not that eating chocolate eventually lowers them cause that would just suck.