The onset and use of non-medical drugs in NZ

Monday 2 March 2009

The onset and use of non-medical drugs in New Zealand

Research lead by the University of Otago, Christchurch provides useful new information on the extent of drug use in New Zealand, and when people first begin using drugs for non-medical purposes.

The data comes from an analysis of over 12,000 interviews of people aged 16 or over carried out by the New Zealand Mental Health Survey (2003/2004), in conjunction with the World Health Organisation (WHO).

The aim of the research is to determine the age when drugs are first used and the percentage of the population who have ever used drugs for non-medical purposes. This is shown for the total population, by age and by ethnicity.

Overall key findings show:

• alcohol is the most commonly used drug, with 94% of the population having ever used it
• tobacco has been used by nearly 51% of people,
• cannabis is the next most common drug with 41% of people having ever used it,
• cocaine is much less commonly used (4.2%) while opioid use (heroin and morphine) is uncommon (2.9%)
• prescription drugs have been used for non-medical purposes by 6% of those surveyed
• nearly 10% have used other drugs such as LSD or glue

These results are similar to those for Australia and the US for all drugs except for cocaine which is four times as likely to have ever been used in the US (16.2%). In contrast the percentage who have ever used cocaine in Colombia and Mexico is similar to that in New Zealand (4.0% for both countries).

In developed countries the use of alcohol is nearly universal, but there are marked variations in cannabis use with New Zealand, Australia and the US all being high use countries. Europe has lower use of cannabis than New Zealand (6.6-19.9% have ever used) and lower use of cocaine (1.0-1.9%) except for Spain (4.1%). The US has a high use of cocaine.

The study also produced some interesting results in relation to the use of drugs by different age groups in NZ. The percentage who had ever smoked tobacco was lowest in younger age groups in 2003-2004, while the percentage of those who had ever used a drug rose slightly between 24-30 years, but then decreased rapidly across the two older age groups.

It is a consistent finding that the percentage of drug users across all drugs is higher for the 25-44 age group than the 16-24 cohort. However analysis of the age of onset showed that this was because many in the youngest age group had not yet started using.

Most people who have tried or used drugs did so for the first time between 16 and 30 years, with few new users at older ages. Alcohol is the drug used first (half had used by around 15 years), followed by cannabis, then opioids and lastly cocaine (in the late 20s).

Ethnic comparisons of onset of drug use were carried out only for those born in New Zealand and aged under 45. Pacific people had delayed onset of alcohol use compared with Māori and the composite ‘Other’ ethnic group, although almost all did use alcohol at least once by the age of 25. For other drugs it appeared that Pacific people were less likely to ever use than ‘Others’, who in turn were less likely to use than Māori.

The researchers say that these results indicate that a range of strategies to combat drug use and abuse should start in adolescence, not only through schools, but also through interventions at national and local levels.

A disadvantage in understanding recent drug trends is that questions specifically on methamphetamine and ‘party pill’ use were not included in the New Zealand Mental Health Survey. An international interview was used in which these drugs were included within drug groups, but not asked about on their own.

The ‘Onset and lifetime use of drugs in New Zealand’ study has been published in the Drug and Alcohol Review and was funded by the New Zealand Lotteries Grants Board. The survey was funded by the Ministry of Health, the Health Research Council of New Zealand and the Alcohol Advisory Council.

www.ouc.otago.ac.nz

For a list of Otago experts available for media comment, please go to:
www.otago.ac.nz/mediaexpertise

ENDS

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