I do not know what other conditions you’re talking about. I will not attempt to explain to you the difference between chronic depression and high blood pressure, research it yourself. The bottom line is that there are certain conditions which require medicine and for which the pilot becomes unsafe if the medicine is not taken. The FAA has determined that some of those conditions require grounding regardless. They do not owe a potential pilot a “right” to fly, they owe the public a safe airspace.