"Hey boss- not going to be able to come in to work today. It's my back..again"
Saying something like this is more than likely going to get an eye-roll from someone..very possibly the person you just said it to.
Possibly more suspicious to the listening audience is when others hear someone is not coming to work for some purported mental health issue. I'm not talking about the now ubiquitous "mental health day" that seemingly everyone seems to ask for and take from time to time in the 21st century. I'm talking about the type of mental health issue often mapped to very serious outcomes..including the most serious outcome of them all. ("Gosh...just horrible..nobody knew").
Unless an illness can be seen under a microscope or from an MRI, a sizable percentage of people think it is a sham. They think the system is being gamed. And it is true there will always be people who will game the system. But most unable to answer the bell for these reasons are hurting, often badly, and they know you don't believe them.
Chronic back issues and mental health are clearly very different things though both can stop people in their tracks. If you are fortunate enough to struggle with neither, I can understand how the idea of carrying your weight- and some of the weight of others- can be disillusioning. Especially when some are claiming they are not well but, in fact, are almost certainly capable of fulfilling their duties. Just remember, however, the ones who are unjustifiably "phoning it in"- be grateful that you are who you are instead of ruminating how inadequate they are. You'll be an exponentially happier person.
People carrying mental health issues also struggle mightily with the stigma. If you feel the urge to judge them or verbally beat them up- they've already beat you to it.
Awareness has been elevated in recent years but there will not be any wholesale change any time soon. It's not a shining moment on our collective humanity. The boss or co-worker who exclaims "I'm getting screwed over" when someone misses work or another obligation is really just exhibiting another shade of victimhood- but not the type typically associated with that word.