I'll try to return to this post tmmr to attempt to explain. I'm feeling really...odd right now. Dissociated I think. Not sure. Anyway. Your mind is everything. What makes you you. Why do you do things? It boils down to pleasure(maybe satisfaction too). Going to the park/talking with friends/travelling brings you pleasure. But with depression, there seems to be something wrong with that part in the brain...doing those things does not bring enough pleasure to be worth the trouble. Also the feeling of pleasure when it comes, is much more fleeting. Nothing brings joy. So it is hard to push yourself to do something when there is no reward(in the form of happy chemicals in the brain).

Plus, you feel extremely tired. The mind seems blank. Like a zombie. Think of when you didn't eat enough and felt really weak. It's like that, but it's not food that's lacking, it's brain chemical stuff. So it's all blank and the brain doesn't seem to have enough 'energy'. I often end up lying down and staring into space, unable to think properly. This means being unable to think about the future. You're just functioning moment by moment.

Inability to concentrate on tasks is another a symptom of depression. Often, there is anguish...not really wholly physical pain or mental pain...a mix of both. Chest hurts, your entire being and soul(for lack of a better word) hurts. And it may be worse than physical pain, because it's not your body that's hurting, it's you. Have you ever experienced a lot of physical pain? You end up being unable to do anything else except devote your entire attention on the pain, lie around and feel like shit. Nothing matters except the cessation of the pain. Same with depression.