[angryprofessor]

>The rate of suicide is high among Grad/PhD students because they have to "think outside the box" every single day. They have to find a "breakthrough".

That's really not true, though many grad students (especially in physics) think it is. You need to make a useful research contribution, but it can be evolutionary.

My thesis problem is a very popular one: new Ph.D.'s are awarded monthly for incremental advances in this area. Only about 2 theses on the topic (in the past 10 years) have actually been breakthroughs. The rest are just marginal improvements, i.e. 1'st order -> 2'nd order -> 4'th order, spherical coordinates -> arbitrary spherical-like coordinates -> arbitrary coordinates, etc.