I would be very surprised to know of 'realized masters' who suffered clinical depression, or needed psychiatric medicine. It's a contradiction. I would think a 'realized master' would understand there is nothing worth being depressed about.
With respect, chemical based mental disorders don't work like that. It's not a matter of things happening which produces sadness, anxiety or whatever. It's more like a constant modification of perception that doesn't as much go away as it is managed effectively. Your brain doesn't focus on winning the Super Bowl, it focuses on the fact that you didn't catch that second pass in the first quarter.
This is very similar to anxiety which I know for a fact at least one highly realized practitioner deals with(Yongey Mingyur Rinpoche, he talked about it in his first book). The only difference between the two is the nature of the overall filter that the brain puts over your perception.
In regards to realized masters it wouldn't surprise me one bit if they suffered clinical depression but managed it well enough that medicine was no longer required. The trick I've found is to be able to differentiate the "depressed" or "anxious" thoughts from the "real" thoughts.
For example, "My car needs coolant quite often. I should take it to the repair shop. It may be something minor or something serious. Either way it should get fixed." is a rational, if not unfortunate thought process. "My car needs coolant, I'm positive it is the radiator, I'm going to be without a car, soon without a job, and will die cold, lonely, and hungry." is the depression talking and should be pushed aside and ignored or "logic-ed" away.
The main difference between people who have to take medication and people who don't is the strength of the "depression talk" in one's head once you take what precautions you can to reduce the volume.