Observations and graphs of numbers institutionalized are discussed by Bernard Harcourt guestblogging at Volokh. His conclusion:
What is also clear is that Seung-Hui Cho probably would have been institutionalized in the 1940s or 50s and, as a result, the Virginia Tech tragedy may not have happened. According to the New York Times, the director of the campus counseling services at Virginia Tech said of Cho: “The mental health professionals were there to assess his safety, not particularly the safety of others.” It’s unlikely we would have taken that attitude fifty years ago.
But the problem is, we would also be institutionalizing another huge swath of humanity — and it’s simply not clear how many of those other lives we would be irreparably harming in the process.