Actually I recall there was a link, in a recent edition of the PsychCentral Newsletter, to an article regarding research that has been done that has suggested that people who have depression have more realistic views of life than to people who are not depressed. If you search for the term: "depressive realism" on the internet, you'll find information regarding all of the research that has been done with regard to this theory.

Also, there is a YouTube channel called: "Suicide-Prevention Resource Channel". If you find that channel on YouTube, you'll find playlists of many YouTube videos related to the topic of suicide prevention. But, in particular, you'll find a playlist of 3 videos of Yale Professor Shelley Keagan (spelling?) discussing the morality of suicide. The playlist is titled: "The Philosophy of Suicide".