Chris had been away at uni for around a year when he started to change.
He developed a few "eccentricities," his brother George says.
There was a series of quite specific personas: designer streetwear with dreams of becoming a rapper. Another visit, decked out in baseball gear, talking of dropping out of uni to play internationally. Later, a vegan, practicing holistic medicine and acupuncture.
"We thought he was kind of becoming his own person," says George.
Before leaving for study, Chris had never really got into drinking. He'd been mostly clean through high school. At uni he'd started smoking pot socially.
Gradually, George says, rumours from Chris' friends started to reach home. They'd talk about his antics from the previous weekend: saying that sometimes, when high, he'd started claiming to have divine powers.
"He'd get quite grandiose, and he's usually quite shy, not super confident. So he definitely had a new lease on life and persona." Over time, George says, "we started hearing rumours that maybe it was a little more than having a good time. People were more like whoa, Chris was crazy last night."
By the time he left uni and moved home, he was smoking every day, sometimes throughout the day, using pot to feel less anxious and ease social awkwardness.
Around that time, George says, "we saw what I think was his first manic episode."
Chris started going to work at 5 AM, taking coffees to clients, in full sales mode. But the enthusiastic early morning visits didn't go down well, and he was stood down.
Depressed, he eventually got back to work in a lower-level position, but was starting to smoke throughout the day. Not long after he decided to try out a sensory deprivation tank—a salt water bath where you float in the dark, silent, immersed in your own thoughts.
George says the tank seemed to trigger something. He stopped turning up to work. Cashing in his savings, he flew around the country, and bought an enormous motorbike. By the end of the episode he'd burned through tens of thousand of dollars—enough money to pay for a house deposit, and had no money left. They found him in the penthouse suite at a downtown hotel. His knee was broken. When one night his aunt went to pick him up, he'd taken a series of unknown drugs, and was literally foaming at the mouth.
It was after the penthouse episode that his family started wondering about mental health.
The question of whether smoking pot can trigger psychotic episodes has been lurking in the background for years now, but it's only in the last decade or so that there's been large-scale research to try and answer it. Exactly how the relationship between cannabis use and psychiatric disorders works is still murky, but it's now clear there's a connection between the two. Reviews of recent studies indicate frequent cannabis use increases the risk for psychotic symptoms by between 1.8 times and 7 times.
"As a kind of rule of thumb rough guide, smoking a joint today is about the same as smoking 25 joints at Woodstock, back in 1969.
Dr Giles Newton-Howes, a psychiatrist and senior lecturer in psychological medicine at the University of Otago, says large-scale population studies in New Zealand and overseas show heavy use early in life increases the chance of psychosis around four-fold. It may not sound huge, but at a population level it's significant.
"Say you were going to play the lottery and you had a 1 in 100 chance of winning, and you could change your odds four-fold, so instead of there being a one in 100 chance of winning there's a one in 25 chance? That's big, right?" he told VICE. "This is the same thing but the other way round. If your chances of developing psychosis were one in 100, would you really want to do something that's going to reduce them to one in 25?"
Over the last 40 years, he says there's been enormous development in terms of potency.
"As a kind of rule of thumb rough guide, smoking a joint today is about the same as smoking 25 joints at Woodstock, back in 1969."
The difference in potencies and chemical makeup make it more difficult to know what you're smoking and how much, and which chemicals are having which effect. Newton-Howes says developing a condition like schizophrenia is a mixture of genes and environment, and it looks like weed can be one of the contributing factors.
"The way I might explain this to families is: you need a combination of stuff to come together, and we don't know how many, or in what proportion. But broad-brushstroke, let's say you need five negative factors to happen and then you develop schizophrenia. Say two of those are your genes, one of those is a deprived environment, one is… your mum drank a bunch of alcohol, and then you smoke a bunch of weed? Then whammo, that could be number five, you've got it."
It was only after Chris' hotel-room bender that George says the family started wondering about mental illness. "It took us a while because we'd always just associated [the highs and lows] with drugs. But then, looking back, it seemed like maybe the last five years had this pattern."
After months of struggling to get him into treatment, Chris admitted himself to the local psych institution. He was diagnosed with bipolar disorder. A few years and several hospital stays later, George wonders what might have happened if he'd never started smoking at all.
"It's hard to say if marijuana sends him either way—because he was smoking every day and having months of high and months of low," he says.
"But I think it was related, it sent him into different patterns."
"For myself, there is this grief. Feeling like my brother might not lead a life that is stable, I don't know if he'll be able to get a good income. He might not have a long-term partner, which I know he really wants."
"There are individuals who are otherwise healthy, with no genetic predisposition, who can be diagnosed with a psychiatric illness purely with cannabis abuse."
Case studies indicate smoking weed can trigger psychotic symptoms in patients with no history of mental illness, that sometimes continue well after the month-long period where traces of the drug should have passed from their system.
One medical team writes about the case of Mr X, a previously-symptom free teen who began to have delusional episodes when smoking. He was arrested while high at his local deli for refusing to pay for his meal, telling staff he was a successful rap artist and had nine billion dollars in the bank. At first his symptoms were temporary, but then they started to stick around even when he wasn't high. He was hospitalised again, this time for two months, which he spent telling staff he owned the hospital, "staring at himself in the mirror and talking to unseen others for hours at a time". Mr X was eventually diagnosed with bipolar disorder with psychotic features. The authors write: "Our case report demonstrates there are individuals who are otherwise healthy, with no genetic predisposition, who can be diagnosed with a psychiatric illness purely with cannabis abuse."
A Dutch study of 4045 people who started out symptom-free, found those who smoked pot were 3 times more likely to exhibit psychosis symptoms three years later. For those using the drug heavily, that increased to 6.8 times. The authors concluded that "cannabis use is an independent risk factor for the emergence of psychosis in psychosis-free persons".
Here in New Zealand, the Otago University Christchurch study tracks 1000 children born in 1977 over their lifetime. Associate professor John Horwood, the director of the study, told VICE the impact of cannabis use is one of the things they've looked at.
While most of their group—80 percent—had at least tried the drug, only about 5-10 percent were daily users for three years or longer.
"In terms of mental health, we see linkages between cannabis use across the board—whatever age—and psychotic symptoms," he says.
"There's quite a range of studies now that look at onset not just of full-blown psychosis but also psychotic symptoms," he says. "Typically they show the more young people are smoking cannabis, the more likely they are to observe adverse consequences." He says regular users are 1.5-1.8 times more likely to experience psychosis.
"At a population level, that doesn't sound like a very big number, but if you think about it … a 70 percent increase in risk of psychosis or psychotic episode is not desirable."
Then again, he says, "If you turn it round the other way, probably the vast majority of users do so without adverse consequences."
And he says even if the negative mental health connections are there, that still has to be weighed against the negative effects of criminalisation, which are far reaching and disproportionately affect Maori.
George, too, says legalising could help people to have better knowledge of their drugs, regulate strength, and get more access to education.
"If legalisation meant education, I would be pro. For a lot of people it can be a great, enjoyable drug, recreational use," he says.
*Some names and details have been changed to protect identities.
If you're in New Zealand and need mental health support try:
Lifeline – 0800 543 354 or (09) 5222 999 within Auckland
Suicide Crisis Helpline – 0508 828 865 (0508 TAUTOKO)
Healthline – 0800 611 116
Samaritans – 0800 726 666
Alcohol and Drug Helpline – 0800 787 797
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