Mental Health and a Busy Schedule

As I get older I start to wonder if staying busy and having a daily routine have any kind of correlation to someone's overall mental health. Does waking up everyday with a daunting schedule and the thought of not being able to relax until late at night prove more beneficial in the long run for an individual than having little to no responsibilities and no schedule to attend to?

I believe each person has a sweet spot for their perfect leisure and work balance. What is yours?