A formerly depressed friend of mine once said to me,

“you known, back in the day when i was feeling depressed, I always thought of giving up on life. But then, one day I got a good suggestion from someone. She told me to listen to the ticking of the clock. The ticking used to calm me down.”

I always wondered what would have happened to him if the battery had ran out…

Anyway, I am not sure this method applies to everyone. For instance, ticking of a clock is not healthy for someone who is in a profession like “Bomb disposal”.