Depression.

It wasn't me  but it was someone from my family. One thing you realise is that mental illness doesn't just effect the person itself, it effects everyone around that person. They are you friends, you family, you neighbours, your loved ones. 

Seeing depression was one of the most heartbreaking experiences I've ever had. And the one who is depressed, it's not their fault, they cannot help but feel what they feel. Seeing that you, I was around her all the time, you, I start to think that maybe it was my fault. Maybe if i called her that day she would not have ended up this way, maybe if i asked how she was or if anything was troubling her it would have made a difference, maybe if i was a better person and cared more she would be happy now.

The first time you notice the difference it is usually too late to stop it from happening. Because the first change is probably so subtle that you just assume she had a bad day. The second time you assume she is just going through a phase maybe it's a project with a deadline she's stressing over, maybe it's because of a day she doesnt want to come and it's making her nervous and sad. It starts happening more often, she stops laughing even her fake laughs come to an end. You still don't realise it because everyone has struggles , everyone has problems and you were too busy with yours.