There are very few resources for kids who show even the most obvious signs of mental illness, and it often takes a violent act to get an adolescent or an adult into the system—at which point it may be, horrifically, too late. We also face the need to balance our ability to commit the mentally ill to treatment involuntarily while preserving everyone's civil rights.
What can we do? The sad truth is that the unraveling of our mental health safety net has been a long process, and to knit it back together will also take sustained effort over time. If you're concerned about mental health resources—and we all should be—you can join the National Alliance on Mental Illness (namiwa.org), the most effective advocacy and lobbying group around. You can call and e-mail your legislators in Olympia urging them to seek more funding—A LOT MORE funding—for help for mentally ill children, adolescents, and adults. (While you're at it, urge them to move with all due haste toward sane gun control in the US, and join the Brady Campaign to Prevent Gun Violence at bradycampaign.org.) And you can donate to organizations that help the homeless and the mentally ill, like DESC of Seattle (desc.org).
Also: Don't use gun violence to demonize the mentally ill, and don't let other people do it. The vast majority of people who are mentally ill are at far higher risk of harming themselves than others—if the opposite were true, we'd have mass killings every day, considering the number of mentally ill people we have on the streets. (Likewise, the vast majority of kids who are loners are just that: loners.) These people deserve empathy and support. If you fear someone you know may harm themselves or others, call the Crisis Clinic at 206-461-3222. This 24-hour hotline is staffed by professionals who can discuss your options over the phone or arrange to have someone come to your home, talk to friends and relatives, and determine the best path to treatment. They can also help you constructively confront an unresponsive loved one about their mental health issues.