ATAT - I doubt your course had anything to do with it. First - I don't believe that any one thing can and two there are a lot of options if a student is overwhelmed by a course - and the choice they make about it is not the fault of the prof.

Every semester I have a couple of students who come to me with some sort of rather severe emotional/mental health issue. For some, an easy answer is to simply drop my course/other courses to lower stress. Sometimes they need to take a semester off to deal with themselves/outside of school things. Sometimes, they simply need to pick a new career path.
But none of it, not even for those who find my courses challenging or me scary, really is about me at all.