I have some first-hand experience...

...with mental illness; two of my closest relatives have been hospitalized. Here's a statistic that you should know (my emphasis): 

More Americans receive mental health treatment in prisons and jails than in hospitals or treatment centers. In fact, the three largest inpatient psychiatric facilities in the country are jails: Los Angeles County Jail, Rikers Island Jail in New York City and Cook County Jail in Illinois. 

The point here (and from Friday's horrifying events in Connecticut) is that society can pay for mental health treatment on the front-end or the back. Right now, America pays overwhelmingly on the back.

P. S. Here's the link to that piece everyone is talking about, "I Am Adam Lanza's Mother." I can relate.