WIDESPREAD USE OF CANNABIS SHOWN

A University of Otago study raises doubts about the law on cannabis use and
highlights the need for more resources to help a minority of dependent users.

The research was based on interviews with about 1000 young New Zealanders.

They are participants in a long-term study involving the university's
Dunedin Multidisciplinary Health and Development Research Unit.

The study, published in the New Zealand Medical Journal on Friday, showed
about 50 percent of young people had used cannabis at least once in the 12
months before their 21st and 26th birthdays.

Research showed at least 75 percent of young New Zealanders had used
cannabis at least once by age 26.

"Recognition of the widespread nature of use should have implications for
social policy, as prohibition fails to dissuade many people from using
cannabis in their teens and 20s," the study said.

Dr Richie Poulton, the study's lead author and research unit director, said
in an interview the law "doesn't seem to reflect what's going on in society".

"Conservatively, three-quarters of young people have tried cannabis.

"All those people by definition have been at risk of a criminal
conviction," he said.

Although the study showed that occasional cannabis use did not have any
serious adverse effect, such convictions could damage employment prospects
and restrict overseas travel, he said.

The minority of casual cannabis users who went on to develop dependence
were the "most problematic" group.

The size of this heavy use group, about 20 percent of users (about 10
percent of the overall population) and its "constellation of accompanying
problems" were "sufficient to warrant immediate and serious concern".

Many dependent users experienced adverse physical and psychological outcomes.

Among the dependent group, 75 percent reported using harder drugs than
cannabis in the past year, and 66 percent reported selling drugs in that
period.

Resources were needed to provide effective prevention and treatment
programmes, Dr Poulton said.

The study also showed more people in their mid-20s were using cannabis than
an earlier study had suggested.

The earlier study, based on United States figures, suggested cannabis use
peaked in the late teens and early 20s and declined quite rapidly thereafter.

More research by the Dunedin unit was needed, including to determine the
extent of cannabis use at a later age, he said.