While I was doing my PhD in my previous position I was diagnosed with a mental illness. I started medication however as a result I could not concentrate very well and it made me quit my previous position. I continued my medication and recently have reduced it. Now I think I am able to concentrate again.
Soon I will have an interview for a new PhD position. I was wondering if I should bring up the matter. On one hand, I think I should be honest to my future supervisor. On the other hand, I don't want to lose the chance by scaring them.
Would you please help me with your opinions?
If I shouldn't bring it up myself, what if they asked me about my previous position? Should I tell everything then?
My personal opinion is that I'd rather you tell me right away. It doesn't scare me to know that there is an issue, but it scares me if there are issues I don't know and that I don't know how to handle.
In the end, you and your adviser are going to spend a lot of time together, and you need to be able to work as a team. As an adviser, I'm going to find out one way or the other at one point, either because you're going to tell me once we have built up a relationship of trust, or because we come upon issues where you find yourself not being able to work at the level you are supposed to and where I will start to suspect something. Better to talk about it up front so that both sides know that there are constraints within which the adviser-advisee relationship will have to operate.
(As a postscript: I don't expect to get a complete description of your illness. It is sufficient if you say something of the form "I would also like to mention one issue that I believe is important for you to know: I have some medical issues that I think I have under control now with medication. However, they do impose some constraints on me; in particular, I cannot do X and I will need accommodations for Y.)