Cannabis is a drug that comes from the sativa plant. the main active chemical in cannabis is THC (delta-9 tetrahydrocannabional). There are three main forms of cannabis: marijuana, hashish and hash oil. Marijuana is the most common and least powerful form of cannabis, consisting of the dried leaves and flowers of the plant.
Cannabis is a drug that comes from the cannabis sativa plant. Its active compound is Delta-9 tetrahydrocannabinol (THC). The higher a plant is in THC, the stronger its effects will be. There are three main cannabis products derived from the plant:
The potency of cannabis can be affected by how it is grown. For example, indoor-grown marijuana tends to be much stronger than that grown outdoors,, primarily because of more standardised growing conditions.
Cannabis is a depressant, meaning that it slows down the messages between the brain and the body. The high from smoking cannabis normally takes effect within minutes and can affect a person for about two to four hours.
Slang
Grass, pot, weed, mull, chronic, dak, hash, smoke, buds, skunk, cabbage, ganja, dope, reefer
Short-term effects
The effects of smoking small amounts of cannabis include:
Greater quantities of cannabis can cause unpleasant effects, including:
Long-term effects
There is research evidence that there are some negative effects of long-term, regular cannabis use.
Currently there is no evidence to suggest that occasional use of small amounts of cannabis causes any permanent damage.
Dependence and addiction
Cannabis can be physically and psychologically addictive. Someone is said to be dependent on cannabis when they experience three or more of these six criteria over a year:
Overdose
It is very unlikely a person could overdose on cannabis, and there have been no reported fatalities directly attributed to it. A lethal dose of cannabis is estimated to be 40,000 times the amount needed to intoxicate a person. In comparison, the lethal dose of alcohol is between just 4 and 10 times the dose required to intoxicate.
Some people can have a bad reaction to cannabis use. Often referred to as ‘greening out’, the person might appear pale and sweaty, feel dizzy, nauseous, and may start vomiting. See our Reducing the harm section for tips on how to deal with ‘greening-out’.
It is illegal to import, grow, sell, distribute, possess and use cannabis in New Zealand. People can be charged under the Misuse of Drugs Act 1975.
Marijuana is scheduled under Class C of the Act, and more potent forms, such as hashish and cannabis oil, are scheduled under Class B.
The maximum penalty for possession of marijuana (Class C) is three months jail and/or a $500 fine. The maximum penalty for importing, cultivating and/or supplying cannabis is eight years imprisonment.
The maximum penalty for dealing (importation, manufacture and supply) a Class B drug (hashish and oil), is 14 years imprisonment. Possession or use offences carry a maximum three month jail term and/or a $500 fine.
Having a conviction for drug offences can have a significant impact on a person’s ability to travel overseas and apply for certain jobs.
In some cases, first offenders or when offending is on a minor scale, a person may be offered police ‘diversion’. This means the accused can avoid the court process and the likelihood of a conviction, often in return for a period of community service, a donation and/or attending an approved counselling course.
Diversion is granted at the discretion of the police, and is not uniformly applied in all regions.
Cannabis is the most widely used illegal drug in New Zealand.
According to the latest Drug Use in New Zealand Survey 2007/2008 published in 2010:
Cannabis is often sold in relatively small amounts. An ounce of marijuana tends to cost around $300. A ‘tinny’, a foil-wrapped amount containing enough cannabis for about three cigarettes or joints, is around $20. Other amounts are often sold for $50 or $100.
Research from The Drug Foundation’s 2009 New Zealand Drug Driving Survey indicated that alcohol and cannabis were the most commonly ‘driven on’ substances, with 67.1 percent of cannabis users reporting driving under the influence of cannabis in the past year.
The Drug Foundation’s message is clear: no drug use is the safest drug use. However, we know there will be occasions when people ignore warnings and use drugs in a dangerous manner. To help keep communities safe we therefore provide information about proven methods of drug harm reduction.
There is growing evidence that cannabis use, especially long-term and heavy use, causes harm to the brain and affects mental health. If users wish to reduce the risks of neurological and psychological harm they should only use cannabis ocasionally.
People who have a history of, or pre-disposition to, mental illness risk harm to themselves if they use cannabis, and should avoid cannabis use altogether.
Do not use cannabis and then drive or operate machinery. Cannabis impairs reaction times and hinders concentration, significantly increasing the risk of an accident.
Combining cannabis and alcohol compounds the effects of both drugs. The effects can be unpredictable and can lead to nausea, vomiting, anxiety and panic attacks. Vulnerable users also put themselves at greater risk of experiencing psychotic symptoms when combining cannabis and alcohol. The compounding effect of these two drugs also increases the risk of ‘greening out’.
If someone is having a bad reaction to cannabis – or ‘greening out’ – they may look pale and sweaty, feel dizzy and nauseous, and may begin to vomit.
The best way to help is to take them to a quiet place with fresh air. Sit them in a comfortable position, and give them water or something sweet to drink (not alcohol).
If they begin to vomit, stay with them. Never leave them alone. Lay them on their side so they do not choke on their vomit. Keep them in a safe spot until they begin to feel better. If they do not improve or their condition worsens, call 111 for an ambulance.
If you feel you or anyone you know needs help, there are a number of treatment organisations you can contact in strict confidence.
DrugHelp is a uniquely New Zealand website for people looking for help with their own or someone else’s drug use. DrugHelp shares the stories, experiences, insight and hope of people who have been there – people who have abused drugs and found a way through. www.drughelp.org.nz
The Alcohol Drug Helpline (0800 787 797) provides free and confidential support for any person concerned about their own or another person's alcohol or drug use. When you call you will talk to an experienced counsellor who is there to listen. You can trust the helpline to provide you with confidential and non-judgemental help when you need it.
The helpline is open from 10am-10pm, every day.
What to do in a crisis
If someone overdoses, becomes unwell, or has a bad reaction to cannabis or any other drug, do not hesitate to get emergency medical assistance. A quick response could save their life:
The scientific and clinical evidence to support the medicinal use of cannabis and cannabis-derived products is not yet overwhelming. However, it is well-established enough to suggest cannabis has therapeutic benefits in treating people with serious conditions such as:
Cannabis provides a 'broad spectrum' effect. For example, patients with HIV/AIDS-related conditions, cannabis can reduce nausea, pain and joint aches, while providing appetite stimulation and potentially reducing anxiety.
Medicinal cannabis is grown and prepared for pharmaceutical use.
Research continues into cannabis-derived medicines, such as sprays, tablets and also extraction methods including vaporisation, so that users can avoid the harmful effects of smoking cannabis.
Under New Zealand law, the Minister of Health has the power to authorise the medicinal use of cannabis products. There have been few applications however, and ministerial approval has been granted for only a small number of patients.
Read the Drug Foundation evidence review and policy paper on medicinal cannabis.
There is growing evidence reliably linking cannabis with mental health problems. However, it remains unclear whether cannabis actually causes mental illness, or whether many people with mental illness are pre-disposed towards cannabis use.
Some claim cannabis causes schizophrenia. Research suggests that for people who are already at risk of developing schizophrenia, cannabis can cause the onset of psychotic symptoms. For this reason, people with a vulnerability to schizophrenia (such as a family history of mental illness) should avoid using cannabis completely.
Cannabis use, particularly heavy and frequent use, has been linked to a condition called 'cannabis psychosis'. Episodes of cannabis psychosis are characterised by delusions, confusion, memory loss and hallucinations and could last several days.
An Australian study, published 2006 in the British Journal of Psychiatry, showed that the more cannabis a person with mental illness uses, the worse their symptoms become. It also found that when they suffer a relapse in psychotic symptoms, they were more likely to self medicate with cannabis to cope.
Recent research suggests the earlier regular cannabis use occurs and the heavier it is smoked, the more likely it is to harm development, achievement, and behaviour, while increasing risk of mental health problems.
Some argue cannabis is a gateway drug – that its use causes people to also try, more dangerous drugs. This argument is often used to justify ongoing criminalisation of cannabis.
Others say there is no evidence that cannabis causes harder drug use. They argue that cannabis is the first drug used by people with a predisposition to drug use simply because it is the most widely available. In countries where cannabis is not readily available, other drugs fill the role of ‘gateway’ drug. Another argument against is that not all cannabis users go on to use other drugs.
A study by Otago University researcher Professor David Fergusson, found a clear tendency for those using cannabis to record higher usage of other illicit drugs, but concluded this could be due to a number of reasons, such as:
In other research cited by the Health Select Committee's 2003 report into cannabis use in New Zealand, it was found that people who had used cannabis more than 50 times a year were 60 times more likely to try other illicit drugs than young people who had never tried cannabis.
However, this study could not identify a causal link with the Committee report concluding: "These findings suggest that cannabis, when used frequently, may be a 'gateway' drug to other illicit drug use, although whether this is a result of contact with the illegal market or an effect of cannabis use is uncertain."
A list of relevant links to further information and resources about cannabis.
www.moh.govt.nz/moh.nsf/indexmh/drug-use-in-nz-key-results-of-the-0708-nzadus Drug Use in New Zealand: Key results of the 2007/08 New Zealand Alcohol and Drug Use Survey.
www.shore.ac.nz Recent trends in illegal drug use in New Zealand, 2006-2008. Findings from the Illicit Drug Monitoring System
www.drugfoundation.org.nz/report/drugs-and-driving The Drug Foundation’s Great New Zealand Drug Driving survey
www.parliament.govt.nz The 2003 Health Select Committee report into cannabis use in New Zealand
www.youthlaw.org.nz Youth Law: A youth information service that includes health and legal information about alcohol and other drugs
www.urge.co.nz Youthline's website containing health and safety information and guidelines for young people.
www.ncpic.org.au The National Cannabis Prevention and Information Centre (Australia)
www.druginfo.adf.org.auThe Australian Drug Foundation’s Drug Info Clearinghouse cannabis factsheet.
www.drughelp.org.nz Uniquely New Zealand website that helps people who use drugs and their loved ones find solutions to the problems drug use has caused.