No, they aren't making choices. If you think with every fiber of your being that the medicine will hurt you, you aren't rationally choosing not to be treated. You are making what seems (to you) to be a good decision, but it isn't based on rational thought. They didn't choose to think this way. They didn't choose to have this disease. They aren't always able to choose to get better.
Depression is the worst thing I can think of - you cannot reason your way out of it.
I don’t care what they’re level of thinking is...if it’s that bad then they need to be in an institute for obviously they are not ‘sane’ enough to be making decisions.