Effectiveness of Alcohol and Other Drug harm reduction approaches: Literature review and Evidence brief
Published: August 2026.
A public health approach to reducing drug harm has the potential to improve mental health and wellbeing outcomes for people in Aotearoa New Zealand. Effective and cost-effective approaches grounded in lived experience and evidence make the biggest difference.
We know that drug use is relatively common, with around 75% of adults consuming alcohol and nearly 20% using illegal drugs annually. While not all use is harmful, drug-related harm can affect individuals, families, communities, and society through health complications, psychological impacts, strained relationships, crime, and economic costs.
Increasingly, drug harm is recognised as something that is not solely linked to individual choice. It is also seen as the result of interactions between the drug, the person, and their environment. Structural factors such as social conditions and public policy play a major role in shaping both drug use and harm.
Therefore, to address alcohol and other drug harm an evidence-based public health approach is needed. This will move beyond purely individual responses and recognise social and structural causes of harm.
Regulation, treatment, and harm reduction should work together in a public health approach. Key to this is understanding how evidence supports various approaches.
This work contributes to our 2025-2029 strategic priority to advance mental health and wellbeing outcomes for people with lived experience of mental distress and addiction and strategic outcome to reduce harm from alcohol and other substance use.
About the evidence brief
We commissioned an alcohol and other drug literature review to provide an in-depth synthesis of evidence on what works to reduce harm from alcohol or other drugs. The focus was on what the relevance of approaches to Aotearoa New Zealand. This review is accompanied by an annotated bibliography of 274 studies.
To ensure this information is more accessible and relevant to a wider audience, we have prepared an evidence brief. This summarises evidence of effectiveness from the literature review. It is focused on what works for policy development and advice. The evidence brief is not monitoring of current services or service performance.
No attempt is made to monitor current services or service performance. The information presented is a synthesis of evidence based on desktop research.
Key messages
The Evidence brief summaries the evidence and provides key takeaway messages for Aotearoa New Zealand. In short:
- A public health approach to reducing drug harm is essential
- Harm reduction is effective, evidence based and underutilised
- Embedding te ao Māori is critical for equitable outcomes
- Treatment is most effective when accessible, flexible, and person-centred
- Policy and funding are misaligned with evidence
- Community and Māori knowledge must be better recognised.