The perception that most people have of mental illness comes from a lot of things.
There is of course the fact that mental illness isn’t a tangible as a physical one. Sure, after a while, you start neglecting yourself, you don’t shower, brush your teeth, you might eat too much or too little, you might even harm yourself. But for the most part, nobody can really “see” your illness, other than maybe you looking depressed.
Additionally, you have the romanticization of mental illness in entertainment and media. “Oh, ‘Girl Interrupted’ is such a great film about a strong woman dealing with her problems”, “Oh, those colorful characters in ‘Cuckoo’s Nest’ were just so fun”. People see a mental illness as a character trait. Something that adds to who someone is, but it doesn’t add anything, it subtracts all the things that make you feel human. This leads to a lot of people diagnosing themselves with an illness to explain their actual character traits, which tends to minimize the suffering of people with an actual mental illness. “Oh, well we all get depressed. You just need to think positive and do something fun! Go have an adventure”. The problem with this line of thinking, is that it assumes that a mental illness is a temporary condition, and not a persistent set of symptoms that manifest on a regular basis. Being depressed is not having depression. Being depressed is having a cold. Having depression is having an auto-immune deficiency.
While I can not speak for all mental illnesses, I can speak about depression and PTSD. Both of which I have suffered from for the better part of 2 decades, and both of which make my life incredibly difficult.
Depression is a mental and social cancer. It seeps into your life, it infects you. It takes you over. All the things you enjoy, the things that make you happy, they become meaningless. Imagine one day you woke up, and your favorite meal in the whole world, tasted like shit. Now imagine that’s what you feel your life is like. Oh, you might get a reprieve once in a while, but it’s like cancer going into remission. You know it’ll be back, and you worry about if you’re going to survive it this time.
Then you deal with the people who try to sympathize with you, but if they don’t have it, they don’t really know. So they try to cheer you up, but it doesn’t work. So they get tired of seeing you waste away, and they stop calling. Because, who wants to be around a Debbie Downer? They’re worried that you’ll infect them with your sadness. Your work declines, because when you can be bothered to get out of bed and show up, you can’t focus. Your performance sucks, and you know it. It’s like you have no energy for anything. Your boss notices this, and because they don’t think you’re actually depressed, because “You seemed fine a week ago, you need to leave your personal problems at home”, you lose your job. So you get more depressed, because now not only are you depressed, you’re alone. You feel like a disappointment. You feel like you’ve failed yourself, your friends, your family, and that everyone would be better off without you.
So here you are, sitting in your room. Every thought is a muddled mess of how much you hate yourself. You haven’t showered, or brushed your teeth in days. You get up to go to the bathroom, but since you’ve stopped eating, you don’t even do that anymore. Your bills are piling up, but you haven’t been able to hold a steady job in years. You have no friends, and even if you do, they don’t want to be around you, because you’re depressing. Because you’ve got no job, you’ve probably got no health insurance to get help. But it’s not like it matters, because you’ve been on so many meds that did absolutely nothing to help, you start to wonder if the meds made you worse, if it’s really just “all in your head”. Because you’ve got no friends, you’ve got no support network. Pretty soon, you’re going to end up on the streets, because you’ve got no job, no one to stay with, and no one to help.
And then, you get a reprieve. Your depression goes into remission, even if for an hour. So when people see you not being visibly depressed, it reinforces their idea that it’s something you can just “get over”. But you still feel it in the back of your skull. Those cancerous cells multiplying, waiting to turn into a tumor, waiting to spread through every facet of your life.