A new mental health test in prisons has led to more than 600 inmates being treated for psychiatric illnesses, depression and anxiety.
The Corrections Department began using it to assess new male prisoners over the age of 18 a year ago and have so far screened more than 6000.
Of these: 300 inmates are being treated for serious mental health problems and another 300 are getting help for depression and anxiety.
The department says it means prisoners are much more likely to be rehabilitated.
However Roger Brooking, a counsellor who works with inmates, said that only 600 are being treated shows the majority of those with a mental illness are being overlooked.
He said even those that do get treated won't get what they need, because of the tight restrictions on prison medication.