This is in marked contrast to early 2013 - before the Psychoactive Substances Act was passed in July of that year - when doctors found that 13 per cent of patients at an acute psychiatric ward in Dunedin had been using K2, a popular brand of synthetic cannabis. The researchers said in the New Zealand Medical Journal it appeared synthetic cannabis could trigger psychosis in those with no history of the mental disorder and those who had had previous episodes.
In today's journal, Dr Glue's research group report on their count of patients in the three months before and after the act's implementation.
Beforehand, there were 42 at Dunedin's emergency psychiatric services who had used synthetic cannabis, compared with 20 afterwards. The frequency of symptoms was similar in both periods: around 70 per cent were depressed, around 25 per cent were paranoid and around 70 per cent were agitated.
Around 80 per cent had had prior contact with mental health services and about 25 per cent were admitted to a psychiatric hospital. The researchers say the reduction in patients most likely reflected reduced availability of the drugs.
Massey University drug researcher Dr Chris Wilkins, however, said some use of synthetic cannabis had continued after last year's ban, probably from stockpiling.
Drug Foundation executive director Ross Bell said some people sought the synthetics because they liked the high or because they could pass drug tests which hadn't kept up with the changing chemicals used by manufacturers.
New drug rules
• 250 products were taken from dairies and other retailers when the Psychoactive Substances Act came into force in August 2013.
• The 41 remaining products, which had interim approval for sale at licensed shops, were banned in an amendment last May.
• In November regulations came into force for assessing applications to supply drugs proven to be of low risk.
• As of yesterday, the Psychoactive Substances Regulatory Authority had not received any applications, which would take around two years to process.
