Methamphetamine users make up 50 percent of young men admitted to Whangarei hospital's mental health unit, a Northland psychiatrist says.
Dr Murray Patton, clinical director of Mental Health and Addictions Services for Northland DHB, said the meth problem in the north is worse than he had expected and was particularly acute among young men.
Dr Patton, who previously worked for Waitemata DHB, said he was "seeing and hearing much more about it here" than in his past roles.
He said about half the men in the in-patient unit have psychosis either caused by the drug or made worse by it.
Whangarei's mental health unit had had to increase security and in some cases ban visitors who tried to smuggle meth onto the ward for addicted patients.
Kaitaia campaigners said the region badly needed a residential rehabilitation facility to treat addicts before they became psychotic. The nearest is in Auckland.
Ricky Houghton, manager of He Korowai Trust, said meth use was rampant in the community and a local rehab facility was needed.
"People are coming to me almost every day and say, 'I'm worried about my son, my mokopuna, I'm worried about my daughter', and I say to them, the answer, 'Are you prepared to lock them up are you?
"Are you prepared to lock all of your valuables up, monitor who they speak to and stay up 24 hours a day and basically keep them under house arrest? Because that is what it requires.'"