I agree with Shy~
If this person is someone that you are not interested in, maybe a letter is the best way. The thing that I ask is this, is being depressed the reason you are not interested in him or is it just not there for other reasons (looks, no chemistry)? If it is because you are afraid to go further because of your depression and you like this person, what a tragedy it would be to let a possibly good relationship go because of something you can fight! Believe me depression takes enough of the things in life you already have, dont let it defeat you by self-doubt.
As far as someone loving you as a "depressed" person, there is no terms to loving someone. The first thing you must have is love and the ability in yourself to know that you are truly good enough for anyone. The first person you must convince is you!!! If you have that than the rest falls into place. I know that there are alot of members here that deal mostly deal with the negative side of what they are dealing with when it comes to loving someone with depression. Unfortunately for these "special" people the biggest battle they fight in life is trying to keep their loved one from being destroyed by depression. I am also sure that these people love their partners even with depression and know that it is the person they fell in love with and just like developing a "terminal illness" it is something that occurs after they have loved a person for many years. In that case I think that it is a matter of how strong the relationship is, not an issue of not loving that person because now they have depression.
In my case, my loved one actually learned about my depression the second day we knew each other. It was something that I kept from so many others but felt comfortable telling this NEW person. Long story short, he turned out to be the biggest HERO in my life in trying to defeat my depression, although we are no longer together, the depression was not enough to destroy his love, it was life in general and the breaking of trust.
There are people that will love you and your depression the best advice I can give is too be true to yourself and if you love someone, dont keep something so important from them.
Remember, although some of us look at ourselves as damaged goods because of depression, I know many people that find treasures in the bin of "damaged goods"!