Mr Key said gaps had been identified in the delivery of mental health services to young people and the package was designed to fill those gaps.
"What we know is that there is quite a lot that we don't know about the system. We don't know what works perfectly."
But what was known was that a disproportionate number of Maori boys took their lives and that boys were more likely to succeed at their attempts than girls.
He still thought mental health workers in schools was a good idea.
"Our expectation would be that a 10-year-old boy would be at school and that at least is a controlled environment where a health worker would at least have access to that young person."
Disaffection among young Maori men and a sense of not belonging are part of the problem, Maori Party co-leader Pita Sharples said. He is campaigning for New Zealand history to be taught in all schools.
In a speech last week, he said Maori children were not achieving well in schools because teachers, with other New Zealanders, were not familiar with the history and traditions that made Maori students who they were.
Familiarity with Maori culture was behind the success of kura kaupapa, immersion schools, he said.
Reaching out
Youthline: 0800 376 633
Lifeline: 0800 543 354;
0508 TAUTOKO: (0508 828 865)
Kidsline: 0800 543 754 (4pm to 6pm weekdays)
Depression Helpline: 0800 111 757