Many people have depression. There are two main factors to depression. It can come from a loss of a loved one and only be there for awhile or you could have a chemical imbalance and it could stay there for a lifetime. Either way it's nothing to apologize for.
This is mainly for the people who know someone with depression. Some tips to help your girlfriend, boyfriend, mother, friend..whoever they may be.
DO NOT BLAME EVERY THOUGHT PROCESS YOU DON'T AGREE ON WITH DEPRESSION. If your loved one has something they want to say or do that you don't agree with please for the sake of there being do not say "maybe you feel that way because your depressed, maybe you'd think differently if you were normal" PEOPLE WITH DEPRESSION ARE NORMAL. 300 million people in the world suffer with depression.
I know you want to help your loved one but if you don't have it, your not going to understand it no matter how hard you try. Just be there for them when they ask for help and if they don't simply say "are you ok?" don't ask why or how because sometimes the person can't explain it and it just makes them feel worse.
Don't get annoyed at the random bursts of sadness, the crying, the "one moment your happy and the next your not" thing. People with depression already feel like a bother so if you aren't willing to let it pass, leave. They don't want to cry but when they do just hug them and let them cry. They don't want to bombard you with their problems but they cant help it. So please try to understand before you assume.
There's going to be good days and there are going to be bad days.
Don't say "your life is amazing how can you be depressed?" you can literally have it all, the great family, the awesome boyfriend, the grades..etc and still have it. It's not their fault. shit happens & people get sad EVEN WHEN they "have it all"
My main advice to you is, love them. On the good days and the bad. if you can't do that...or if you can't just accept it without understanding it...leave and if your willing to stay through it all you are SO loved and appreciated, I promise.