New Zealand cannabis hospitalisations more than double in decade - Ministry of Health

New Zealand's cannabis-related hospitalisations have more than doubled in the past decade.

New statistics, collected by the Ministry of Health, show that in 2008 only 192 people were released from hospital with a primary cannabis diagnosis. However, by 2018, this had increased to 505.

Statistics showing the increase.
Statistics showing the increase. Photo credit: Newshub

What could be causing the rise?


Otago University Professor Joseph Boden, who has been appointed to New Zealand's expert panel on cannabis, says the increase is probably due to a combination of factors.

"One is that people are more aware these days of the harms associated with cannabis, and may be more accurate in attributing their symptoms to their use of cannabis," he told Newshub.

"Second is that [as] in overseas jurisdictions, cannabis use is becoming more normalised, so patients may be more willing to admit to it during a medical examination in the ED.

"Third is that there may be some error of measurement, such that patients say that they have used cannabis when they have in fact used synthetic cannabis."

In addition, the statistics show a mixture in the cause of hospitalisations, with some due to acute intoxication and poisoning, and others associated with problems due to long-term heavy usage.

"In the case of psychosis the latter (long-term use) [is causing admissions], particularly for people with a family history of psychotic illness," Prof Boden told Newshub.

Professor Joseph Boden.
Professor Joseph Boden. Photo credit: The AM Show

What age groups are at risk?


While those in their early teens escape relatively unscathed, the numbers jump dramatically over 15.

In 2017/2018, 97 people between 15-19, 147 people between 20-24 and 90 people between 25-29 were hospitalised primarily due to cannabis.

The ages of those hospitalised.
The ages of those hospitalised. Photo credit: Newshub

This adds to concern over youth consumption of cannabis. Prof Boden, who is the director of the Christchurch Health and Development Study (CHDS), a long-running study which has helped reveal the effects of the health-related harms.

In an article for the University of Otago magazine, he explained what research on youth cannabis use has found.

"Younger and heavier users are at greater risk of developing psychotic symptoms during periods when they are not acutely intoxicated by cannabis," he wrote.

"Data from the CHDS suggest that those using cannabis daily at some point prior to age 21 had an 80 percent increase in risk of psychotic symptoms by age 25."

The Government has proposed the legal age of 20 in its draft legislation on recreational cannabis law reform, with Justice Minister Andrew Little saying this is a trade-off.

"We know that the medical science says that the human brain is still developing up to the age of 25, but if you put too high an age on it you just encourage the black market," he told Newshub in May.

Hospitalisation rates decreased with age, although the elderly were still affected. One person between 75-79, two between 80 and 84 and one person over 85 were hospitalised as well.

Overall, Prof Boden says usage rates have remained generally stable amongst older people, and are dropping in younger age groups.

Is our cannabis becoming too strong?


Prof Boden says higher THC-level strains could be becoming more common, although he cautions this is speculative.

Tetrahydrocannabinol - or THC - is the main psychoactive compound in cannabis. It's responsible for the mental changes many find enjoyable, including euphoria and relaxation.

However excessive consumption can cause 'greening out' - overwhelming sensations of nausea, anxiety and paranoia.

Worldwide, there has been an increase in the amount of THC in cannabis over the past few decades, which could increase the risk of adverse psychological effects.

"In general THC levels have increased over the past few decades, but that is the case everywhere," Prof Boden says.

"Other admissions may be due to consuming high doses of high THC content cannabis."

The 2018 National Cannabis and Crime Operation undertaken by New Zealand Police recovered over 50,000 cannabis plants.
The 2018 National Cannabis and Crime Operation undertaken by New Zealand Police recovered over 50,000 cannabis plants. Photo credit: Newshub.

Unfortunately, testing for changes in New Zealand's cannabis isn't done in a comprehensive and systematic way.

"Due to insufficient sample numbers from the testing that has been carried out, and without the sound sampling procedure we would expect from a coordinated survey, we are unable to provide you with reliable data on this important matter," Cameron Johnson, senior scientist - drug chemistry at the Institute of Environmental Science and Research Limited (ESR) told Newshub.

Are we doing enough to support cannabis addiction?


"There's not enough substance use treatment available full stop," Prof Boden says.

"This sector requires more funding to provide services to those in need (which has been recognized both by last year's Mental Health Review, and acknowledged in the 2019 Budget)."

Overseas, legalisation has led to an increase in the tax take. Since legalising cannabis in 2014, Washington State has raked in $1 billion in tax revenues, almost 80 percent of which has been directed towards health and judicial systems, the Guardian reports.

If implemented in New Zealand, Boden says he would like to see the money raised used to help combat drug addiction.

"I think that money should be taken and turned around into improving treatments," he told Newshub in June.

What does this mean for New Zealand's cannabis reforms?


New Zealand is currently heading towards reforming its cannabis laws, and views are split on whether this will increase or decrease our problems.

"The evidence shows the number of hospital admissions rise when recreational marijuana is legalised, in Colorado there was a threefold increase in emergency room visits," says Paula Bennett, National's spokesperson for drug reform.

"The increase is because of wider availability of recreational marijuana, combined with limited education on the harms it causes, and a natural willingness of people to try it once it becomes legal.

"We can't rule out children getting their hands on marijuana mistakenly if edibles, drinks and lotions are available. They are marketed to appeal to younger people."

A map showing the hospitalisations by North Island DHBs.
A map showing the hospitalisations by North Island DHBs. Photo credit: Newshub

Family First national director Bob McCoskrie says the fact remains there is no 'safe drug'.

"These stats will only worsen if marijuana is legalised in New Zealand and the marijuana industry floods the market with highly potent cannabis concentrates - edibles, dabbing (smoking highly concentrated THC) and vaping - as they have in all other jurisdictions where dope has been allowed," he told Newshub.

"This should sound the warning bell that marijuana is absolutely a health issue, which is why the law is so important for protecting public health and safety. A soft approach would be a disaster."

"At a time when New Zealand's mental health system is bursting at the seams, why would we legitimise a mind-altering product which will simply add to social harm? It's patently obvious that legalisation will increase its use and harm. So-called 'regulation' doesn't change the fact that drugs harm."

A map showing the hospitalisations by South Island DHBs.
A map showing the hospitalisations by South Island DHBs. Photo credit: Newshub

However, Green MP Chlöe Swarbrick says legal regulation increases public health outcomes and reduces harm.

"Drug dealers don't check ID. Legal regulation of cannabis will introduce a framework to control access and provide limits on potency, and introduce meaningful education about risks, which is presently left to guesswork," she told Newshub.

"Under cannabis prohibition, New Zealanders have continued to use the substance, but without any regulation on potency, age restriction nor education about potential risks.

"We must take addiction and substance abuse issues out of the shadows - where we have unknown people selling unknown substances of unknown potency to unknown people who consume them in unknown places - and into the light of legal regulation.

"Ultimately, this reduces harm, increases oversight and resource for services, and means New Zealanders have the information to make informed, educated decisions for their wellbeing".

And Prof Boden also agrees that a framework for regulation would help reduce harms.

"If people were able to have access to a safer product (e.g. labelled, limits on THC levels), then yes," he says. "Drug dealers don't put labels on their cannabis."