In an ideal "patient-centred" health care system, cases would be assessed individually, their needs determined, and a way found to address the needs. But we don't have such a system. What we have is a patchwork of "programs'  run independently by various institutions. People apply to join the programs and are accepted or rejected. Even if one is accepted into a treatment program, the child (or adult) is free to leave at any time, so the most seriously mentally-ill tend to drop out or refuse to take their medication, and the programs end up catering to the highest-functioning members while those most in need fall by the wayside. 
The psychiatric "catch-22" is that the seriously mentally-ill are assumed by law to be competent to decide on the consequences of accepting, or rejecting, treatment. So they are "free" to end up on the street (60% of the homeless) or dead. Allowing the seriously mentally-ill to direct their own treatment is like giving car keys to the blind.