Why is it that depression is so random and hard to detect, that even the happiest person turns out to be the worst mentally?

Because sometimes people have depression without knowing the reason. Even the happiest person may have a problem that he's or she's afraid of telling so keeping it inside might lead to deppresion

No one wants to cause other people to be upset, and that keeps people from talking about the problem. They don't want to upset other people, so they act like they aren't upset.

It is because, the happiest people aren't the happiest. They pretend to be happy so no one would know why they're sad. In fact the very reason why depressed person is sad makes it feel inferior. Perhaps, I don't have friends. I'm too ashamed to admit it. I put on my happy mask and just blend in with the crowd. No one knows ... how what matters in my heart. That makes it more painful, the fact that NOONE, feels a damn about what you are inside that happy mask ...

People often fake a smile and pretend everything's okay when it's not. They do this to not see like an attention seeker or because they feel like their feelings don't matter. Your feelings do matter.

Because people tend to assume many things about depression, and also, there are no physical tests on depression so it's much harder to diagnose than some other disorders.

Because depression isn't just a feeling. It's not having uncontrollable tears or something similar to that. To me, its this state of being, a sinking feeling made up of many feelings. And it's just easy to mask after a while, because it's just..there all the time. It doesn't take a lot of effort to wear a smile and say "I'm fine" but it's much much harder to open up and cry and be honest.

Often people suffering from depression hide their emotions, in a sense, "put a mask on". I was one of those people. To make sure people around me wouldn't get affected negatively from my depression, I made sure I was extra peppy and happy around friends, but at home, I'd sit and cry and hours not wanting to do anything. Of course, now I'm better, but that is my belief as to why depression is so random and hard to detect.

Depression is a force nature. It can strike anyone. Rich or poor. Black or white. Christian or Hindu. Depression does not a certain group of people but everyone. We may not be able to control it but together we can support each other during our darkest days.

Depression is a neurobiochemical imbalance, for one thing, and can affect anyone at random. It is hard to detect, because different people respond differently to it, and some people can be really good at covering it up. The happiest-seeming person could just as well be the saddest, and their liveliness could be a compensatory mechanism for themselves and others. They are often the most compassionate, so it's not wonder they'd want to keep everyone else worry-free! In addition, it can be a comorbidity with bipolar, in which case what you may be seeing is their manic side in public, with their depressed side remaining behind closed doors.

I think that the most emotional or depressed people are the best at concealing their emotions, because they may be scared, or in some cases, unable to express their emotions to people close to them. In the same way, I think that the most hurt people, also are the most caring people. They have been through the worst seasons, and they care to ensure no one goes through the same things as they had gone through. This is an important reminder to of course, care about your friends that are visibly struggling, but also to check in with your happy friends, because underneath, they may be going through something as well.