I'll use myself as an example. I suffer from extreme ADHD, its medicated, but I can't take the stronger stuff like adderall because of my anxiety, and OCD tendencies. This makes it difficult to do very mundane tasks again and again, which is a customer service job like I have. I do my job well, and I get results, I just get harassed if I don't notate something in particular way, or follow a rigid guideline for procedure. So with ADHD, it make me feel like I have to work twice as hard, and be thrice as miserable to even be considered for a decent, non zombie shift.