CANNABIS USE LEADS TO HARD DRUGS - STUDY

Regular or heavy cannabis users are significantly more likely to use
other illegal drugs than non-users, according to a Christchurch study.

By the age of 25, eight out of 10 people have tried cannabis and more
than 40% have tried at least one other illicit drug, mostly ecstasy,
LSD and amphetamines, according to the Christchurch School of Medicine.

Lead researcher Professor David Fergusson said that after eliminating
other factors, the link between cannabis use and other illegal drugs
was significant. However, the underlying cause remained unknown.

This link - which emerged from Fergusson's 25-year study of 1200
babies born in Canterbury - varied dramatically with age.

"If you started (smoking cannabis) at 23, you are at a far lower risk
than if you started when you were 15."

Fergusson said it was possible cannabis changed a young person's
brain chemistry, and made that person more susceptible to illicit
drug use, or that experiences with cannabis encouraged
experimentation with other drugs.

It could also be that buying cannabis from drug dealers exposed young
people to other illegal substances.

He believed his research would be seized on by both sides of the
cannabis decriminalisation debate.

"One will say this shows how terrible cannabis is; the other saying
this shows how terrible the cannabis laws are."

Evidence of cannabis opening a gateway to other drugs was used in the
United States to argue against decriminalisation, he said.

"But in Holland they said by making cannabis illegal it encouraged
otherwise law-abiding citizens to mingle with drug users, and
therefore we should break the links between cannabis and illegal drug markets."

Fergusson said the gateway effects were probably due to both personal
and social factors. He added that previous evidence from his
longitudinal study showed that while high numbers of people tried
illegal drugs only a minority suffered adverse effects.

Of the 80 per cent who had tried cannabis, 10 per cent reported heavy
use at some time in their lives, and 5 per cent were using it daily.

He said the current cannabis laws were not working well and urged
gradual changes, such as removing the penalties from cannabis use,
with each change scientifically evaluated.

Paula Lambert a member of marijuana law reform group Norml, welcomed
the latest research as a factual contribution to an otherwise
irrational debate.

"People who gorge on sugar and alcohol don't get the same moralistic,
judgmental negative attacks. It's almost hate speech."

Drug and Alcohol Practitioners Association chairman Tim Harding, who
is also chief executive of rehabilitation organisation Care New
Zealand, said cannabis use should be seen as a health issue not a moral one.

He did not advocate decriminalisation, fearing this could send the
message that cannabis was harmless.

"There is no way it is harmless. People using cannabis don't kill
themselves quickly, but, over time, if they are regular cannabis
smokers, they can seriously damage not only their health but also
their future and raise their likelihood of mental illness quite markedly."

He suggested a diversion scheme for everyone arrested on cannabis
charges to give them advice and to assess their risk of dependency.

National Addiction Centre director and Canterbury psychiatrist Doug
Sellman said "the worst thing that could happen is legalisation and
commercialisation" of cannabis because that would increase use.

The drug could cause memory problems, increased susceptibility to
infection, and made it dangerous to drive or operate heavy machinery.

Drug squad Detective Sergeant Greg Murton said some dealers sold only
cannabis but many dealt in a range of drugs.

"Tinny houses do not generally offer anything else, but there are
street-level dealers who will deal in anything they can get their hands on."