Ohio State has seen a 43% jump in the past five years in the number of students being treated at the university’s counseling center. At the University of Central Florida in Orlando, the increase has been about 12% each year over the past decade. At the University of Michigan in Ann Arbor, demand for counseling-center services has increased by 36% in the last seven years. ... It is unclear why the rates of mental-health problems seem to be increasing among college students. Therapists point to everything from the economy and rising cost of tuition to the impact of social media...