I honestly don't even know why the glorification of mental illness is an actual thing. When did it become cool to have some sort of psychological disorder that interferes with living a normal life? Maybe the whole angsty punk scene from the early 2000s left a lot of young people with a new appreciation for darker feelings that developed into the idea that feeling bad is actually good. Honestly, I don't know and most of me doesn't ever want to know.
Maybe it's something that you need to experience firsthand to see, but there is nothing pretty or romantic or cool about struggling with a psychological disorder. Depression is not poetic. Eating disorders are not beautiful. Self-harm is not admirable. Anxiety isn't cute.
Those of us living with mental illnesses are fighting a constant battle just to do daily tasks. A lot of us may not be open about our disorders, and there are tons of us who are high-functioning individuals; you would never know by looking at us or talking to us that we have a mental disorder. The face of depression is not that emo kid from middle school who wore too much eyeliner and covered their face with long bangs. Those of us who are fighting depressive and other mental disorders are normal people with all sorts of jobs from all sorts of backgrounds. We are humans, not your aesthetic (see below).
Maybe it all comes down to understanding. Without directly experiencing mental illness, people have only what they're told or what they see to define what life is like with a mental disorder. People tend to think they know it all, but the truth is that no one really knows what it feels like to suffer from a mental illness unless they've experienced it themselves. Words like "depression" get boiled down to a vague, short definition--in this case, "sadness"-- when in reality it is something much more complicated than that. Depression isn't simply sadness; it can be irritability, insomnia, lack of appetite, lack of enjoyment, inability to focus, or countless other combinations of symptoms. Each individual experiences mental illness differently, too. One person who has depression might also suffer from insomnia, but someone else might be tired and asleep all of the time
Another huge misconception is that being sad is the same as having a depressive disorder. Most, if not all, people will experience a depressive episode at some point in their lives, but a much smaller number will be diagnosed with a mood disorder like depression. Being even extremely sad for a period of time is normal at certain times in our lives, but a mood disorder is considered when this sadness lasts for a long period of time and begins to interfere with one's daily life.
The same goes with anxiety and other psychological disorders. Being anxious or stressed is normal in certain situations, and doesn't mean you have an anxiety disorder. You are not bipolar if your mood changes quickly--people with bipolar disorder experience severe mood swings over a long period of time, not from minute to minute--and you do not magically have ADHD if you're not paying attention in class.
Using the names of real disorders to describe normal human behaviors is really discrediting to those who actually do suffer from the illness. Saying you must be "bipolar" because of a few hormonal mood swings implies that having bipolar disorder isn't a big deal, which is definitely not true. Please, don't ever joke or exaggerate that you're going to kill yourself. Suicide is not funny and every mention of it should be taken very seriously.