1990s to early 2000s
During this time, adolescents drank more often and heavier amounts in a drinking occasion . From 1995 to 2000, females 18-19 years of age showed the largest increases in the prevalence of drinking, the number of occasions drinking in a year, and the amount consumed in an occasion. These marked increases were likely to have followed the new Sale of Liquor Act (1989) and its subsequent amendments in 1999 .
In 1999, the minimum legal purchase age was reduced from 20 to 18 years. Research showed this this law change was associated with an increase in a number of alcohol-related harms for young people, including alcohol-related hospitalisations , prosecutions for driving with excess alcohol and disorder , and traffic crashes [5,6].
Following the turn of the century, the early 2000s saw some changes in adolescent drinking.
By 2004, the number of current drinkers was declining in both girls and boys . However, the usual amount of alcohol consumed in a drinking occasion had not changed .
Data from the National Youth Health Survey found little change in the number of students that were drinking weekly from 2001 (16.9% of all secondary students) to 2007 (17.8%).
Four in every ten students (40%) were binge drinking at least once per month in 2001, which decreased in 2007 to 34.4%.
Following 2007, there have been continued declines in the the number of adolescents drinking, and among those that do drink, the number of drinking occasions per month is declining .
In 2007, 61% of all students were current drinkers - this declined to 45% in 2012. The prevalence of weekly drinking declined from 17.8% in 2007 to 8.3% in 2012.
The prevalence of binge drinking was 34% in 2007, declining to 23% in 2012.
The data from the National Health Survey is supported by data from the New Zealand Health Survey.
Drinking in the last 12 months among 15-17 year olds
The New Zealand Health Survey shows 150,000 fewer 15-17 year olds drinking in 2016/17 than 2006/07. This is a fantastic change to see - but we still have a long way to go as over half of all young people in this age group are drinking.
Hazardous drinking among 15-17 year olds
We have witnessed great declines in the prevalence of young people being classified as a hazardous drinker. ‘Hazardous drinking’ refers to an established alcohol drinking pattern that carries a risk of harming the drinker’s physical or mental health or having harmful social effects on the drinker or others.
The prevalence of hazardous drinking from the New Zealand Health Survey is shown below. The number of hazardous drinkers almost halved from 2006/07 to 2015/16!
The question in the survey then changed, so using the new question only comparisons can be made from 2015/16 onwards. This shows the following:
The heavy style of drinking is showing little change
However, the fewer drinking occasions has not been accompanied by any real changes in the typical quantities consumed in a drinking occasion . Whilst young adolescent males (<16 years) in New Zealand are showing some positive signs of decreasing the amount of alcohol they consume in an occasion, the quantities consumed by older adolescent males and females has not changed. Of significant concern, young adolescent (<16 years) females living in households and neighbourhoods with low incomes are showing higher typical quantities consumed over time. The finding that young girls are reporting more hazardous drinking patterns over time is consistent with studies conducted in the United States  and Spain .
The reasons for the fewer drinking occasions in New Zealand warrants further research, but could be due to changing recreation activities for young people, e.g. social media, alternative activities, etc. Therefore, the heavy drinking culture may have changed little among New Zealand adolescents; rather, some recreation and social activities are currently replacing drinking occasions. The finding that paid employment among New Zealand secondary students has dropped from 38.9% in 2007 to 26.2% in 2012  may also assist to explain the reduced frequency of drinking occasion in the current environment.