Medical info on job applications in Taiwan

I am filling out job applications for EFL teaching jobs in Taiwan and they are asking for a lot of medical questions.They are asking about current illnesses and medication which makes sense, but they also want to know "Have you ever suffered from, or been treated for, depression, anxiety, or any other mental or mood disorder?" I have in the past, but no longer. How far back in my history should I go? Will things like being treated for anxiety hurt my job opportunities? Will they be checking with my doctors? If I don't put anything down could that bite me in the butt later?

I have ADHD. Based on my research as long as I go to Taiwan with a valid prescription and medical documentation getting meds from a doctor there shouldn't be an issue. My question is- could/will taking Ritalin affect me being hired? Should I declare that I take the medication on my applications? If need be I could stop taking it so I doesn't show up on a drug test (it would make focusing difficult but it's doable.) Do they even test for Ritalin or is just serious diseases?

I'm worried about cultural stigmas on these things as well. I also have mild asthma and allergies and I take birth control because I have endometriosis. It just seems like I'm having to tell these people a lot of information. Do I have to? If I don't put this stuff on my application and then go there and get medication from a doctor will that be an issue?

None of my medical conditions affect how I work nor are they contagious diseases.
I appreciate all help!