Today is the final of a six-part series on the damage methamphetamine is doing to New Zealand and what we can do to fix it.
Students at some Northland schools are signing up for voluntary random drug testing to prove they can stay clean for a year.
Under the Rubicon drug education programme, students who get into trouble for using drugs can sign a contract to attend counselling sessions and stay drug and alcohol-free for 12 months.
Part of the agreement is that they can be randomly drug tested at school up to three times a year.
Bream Bay College principal Wayne Buckland said his school found about 25 students using drugs each year.
It used the programme because nearly all students completed it successfully and it helped teenagers who had used drugs resist peer pressure to use them again. "They just say they're on Rubicon."
But few schools appear to be keen on random drug testing across all students, as introduced in parts of the United States.
Methamphetamine consultant Mike Sabin, who floated the idea in a paper to a parliamentary select committee last year, said he did not necessarily recommend compulsory testing in all schools.
But the idea of screening students for drugs had two main benefits - it allowed young people with drug problems to get help early and gave all students an excuse to say no, in case they were caught.
Mr Buckland said that he could not see a lot of benefit in testing all students and it seemed philosophically wrong to do so if they had not been found using drugs in the first place.
Another Northland school which announced plans to introduce random testing for all pupils three years ago has backed away from the idea.
Otamatea High School board chairwoman Lynda Lewin said the school found it was difficult to be sure how long ago drugs had been taken and "we can't control what they're doing outside of school".
The school had twice tried sniffer dogs, which found a few students with drugs the first time and no one the second time.
In the end it also signed up with Rubicon, which has links with police and the local area health board, because it offered a more positive service, including counselling for families as well as the students.
Last year a report by the Australian National Council on Drugs found no evidence that drug testing in schools acted as a deterrent or reduced the harm caused by drugs.
It estimated that drug testing every Australian child once a year could cost about A$355 million ($452 million). Annual tests on a random 10 per cent of the school population three times a year could cost up to A$110 million.
The study also raised questions about the accuracy of testing and the ethical and legal implications such as children's rights to privacy.
