Just how do you tell someone you're worried about their drinking or drug use?
Thousands of New Zealanders are expected to anonymously divulge their drug use in a survey of illicit behaviour around the world.
But how do you tell someone you're worried about their alcohol intake or their drug use?
Global Drug Survey founding director and consultant psychiatrist of addiction medicine Dr Adam Winstock said an important part of promoting harm reduction involved sensibly approaching a friend or family member if you're worried about them.
The survey, which investigates how people get high around the world, has about six weeks to go and so far 68,000 people have divulged their usage.
In 2015 the survey revealed how more people were using the internet, in particular the underground sites of the "dark web," to buy drugs and other illegal materials online.
Results backed up widespread reports that synthetic cannabis and its derivatives were more likely to lead to a hospital admission for adverse reactions.
Synthetic cannabinoids, during 2013 and 2014 in New Zealand, were sold in a regulated market until the Government passed emergency legislation banning legal highs and products like Kronic.
In an online seminar on Friday, Winstock said it was often friends or family members who spotted problems early.
They outrank other available responses, such as drug and alcohol treatments, anonymous services and doctors.
"The earlier you can intervene the easier it is to change behaviour.
"Conversations can change our relationships within the world around us. We want to make drug use safer, regardless of legal status. You can legalise cannabis tomorrow but it doesn't necessarily make it safer.
"The more intoxicated people get the less insight they have into the people around them."
Self-reporting was difficult as many people with potentially problematic behaviour tend to over-estimate their personal immunity to harm. So they tend to think "I'm OK," or "my friends are doing it too", or even "I'm just like everyone else."
And, of course, many people say "I like getting high" and derive pleasure from drinking and recreational drug use, he said.
Winstock said the things that worried people most were the amount used, the impact on health and the effect on behaviour and relationships. To start a difficult conversation it was important people think about what they want to say.
"Start by being positive about the person, their qualities as a person and why you are mates.
"Say you're worried but not sure if you need to be and focus on behaviours and actions, not the person.
"Don't argue and don't get into arguments about their drug use. Everyone is different. Some people run into problems early or more easily than others."
One approach is "do, not say."
In other words, instead of drinking or taking drugs tell your friend or family member you're worried and you'd like to take a break.
"You can encourage the idea of change without having a conversation.
"If you're a regular drug using friend you might want to share a period of reduced use to support them."
Of course, a conversation during which you tell someone you're worried about how much they drink, or their behaviour around drugs, might not always go smoothly.
One thing to remember is ending that talk.
Winstock advises people highlight how it hasn't been easy to broach the topic and it's important to remember that a reluctance to talk is not the same as caring or sharing concerns.
And remember to say "thank you."
The anonymous online survey running in New Zealand and 18 other countries is expected to gather information from more than 100,000 people worldwide. Stuff.co.nz is one of the media partners.
Winstock said New Zealand was interesting in terms of legality and drug use patterns. Since the ban on legal highs it appeared that the rate of use here has fallen but, importantly, there was evidence to suggest increasing rates of dependency on synthetics among the remaining users.
"The bit that's interesting is people becoming dependent and people ending up using them repeatedly. People are falling into dependent use of synthetic products."
Those users tended to be at the lower end of the socio-economic spectrum and synthetic cannabis was around 30 times more likely to result in a user being admitted to hospital, he said.
Aims of the survey include alerting people to dangers, encouraging safe use and promoting harm reduction.
"The vast majority of people who take drugs are socially well-adjusted, otherwise law abiding and neither seeking, nor in need of, medical treatment.
"Sometimes, though, they overdo it or make bad choices which endanger themselves and/or others."