to me, Love is the greatest thing of all. However, I think love is not limited to an individual. People commit suicide due to a 'loss' of a 'love' that they value at the highest level. That 'failed' love could be job loss, breakup, divorce, money, bankruptcy, etc.
The only thing that can trigger a suicidal depression in me is my love for my career. From what i know about myself after all these years, the moment I quit my job, I would go suicidal. I think I practically worship my career more than anything in the world and thats very wrong of me.