Here's an idea out of left field. I get the sense that most psych research is looking for economy at scale (easy things that make a small difference in entire populations) or narrow results (eg., exercise improves depression). But has anyone looked at creating the absolute optimal conditions for psychological health?
Obviously there'd be objectivity and IRB challenges. But from my perspective as an engineer, we need our Formula One racetracks and Large Hadron Colliders -- the places where we throw millions of dollars at getting everything as perfect as possible for just a handful of samples.
What if the fate of the world depended on the rehabilitation of one random person's neuroses? Given their cooperation and unlimited resources, how would we create the best imaginable conditions to overcome their bipolar or narcissism or addiction?
Or, what if we held a psychological olympics every four years? What would the events be? How would you train someone to win each event -- to be the world's champion at that aspect of psychological health? And how would we train someone to win the Overall Health medal -- the Mr./Mrs. Universe award for best specimen of optimal health?