Coming from a depressed person and (anecdotally) a competent liar when it comes to all mental health professionals I've met so far, I am not intent on killing myself presently, and would do anything I could to take this opportunity if it arose. I expect it would be exceedingly difficult to find mentally healthy (or untreatably depressed) people for such purposes, or to have effective tests to differentiate them from treatably depressed people.

For people with submissive tendencies, being rewarded and punished by a dominant to shape behaviour could be an effective way to be motivated. Doing things you should be would be a sexual pleasing-my-master type of enjoyment, and when you make mistakes or fail to meet your goals perhaps punishment could reduce giving up or being demotivated for too long.