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.
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.