If its still relevant.. I would like to share my story.
A vocalist, is afterall a human with emotions. We do, like others experience sadness and happiness. What makes us different from others is that, we tend to express our moods and feelings through singing as a medium.
Hence, by being able to let out heartfelt emotions with singing, we, on the other hand, will be more able to get out of depression easily.
However, it is some part of truth in that we as vocalists gets more down times than others. It is a necessary "evil".
WhY? Like Gandhi demostrated, you cannot ensure a disease be cured by your own medicine unless u tried the cure on yourself first.
To let others know about the feelings in a song, a vocalist must first feel that emotion him/herself, then he/she would be able to channel the essence of the song to others.
In conclusion, vocalists do become depressed more frequently than others, as it will enhance our feel in singing to greater heights. We do it for the greater good, so that our audience out there, can appreciate our art even better.
Hm.
I think i spoke in too serious a tone. MANZ.. I GOTTA SLACK! SLEEPING TIME! ZzZZz..