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Two new studies published today in the Lancet, highlight that mental and substance use disorders are the leading cause of non-fatal illness worldwide (Whiteford et al; Degenhardt et al). These two studies are a valuable contribution to knowledge about health problems and come from a massive international research project. The results should help guide policymakers around the world in taking the cost-effective steps needed to prevent and treat the high health burden from mental and substance use disorders.

Actually, from the New Zealand perspective, these international findings are largely compatible with those from New Zealand’s own national study on health loss. This Ministry of Health work was only just released a few weeks ago. It shared key definitions and methods with the Lancet studies, but the New Zealand work had access to more local data.

The Ministry’s study also found that “anxiety and depressive disorders” were very important. Indeed, these were the second most important cause of health loss after coronary heart disease (but for NZ women they were the first cause of health loss, ahead of heart disease). The New Zealand study also reported that among youth (aged 15–24 years), alcohol use disorders were the leading cause of health loss (14% of the total for this age group), followed closely by anxiety and depressive disorders.

The Lancet paper on mental health and substance use reported that “cost-effective interventions are available for most disorders”. Indeed, some responses would probably be cost-saving to the government and to society – eg, higher alcohol taxes. Increasing alcohol taxes are well proven to reduce alcohol-related health harm – and would probably also reduce social damage from alcohol-related crime and violence. There is also evidence from a systematic review that there are other cost-effective alcohol controls, such as marketing restrictions. The likely reason that successive New Zealand governments are chronically weak in the alcohol control area is probably concern about offending commercial interests involved in the production and sales of alcohol. Certainly most of the New Zealand public supports tighter alcohol controls, given polls conducted during 2011-2012 over new alcohol legislation.

Although alcohol is a bigger problem than illicit drugs (several times bigger in health loss for NZ), illicit drugs still cause significant health loss. This is from suicides, fatal overdoses and infections from drug injecting (eg, HIV/AIDS and hepatitis C).

New Zealand was a world leader in harm reduction from illicit drug use by adopting a needle and syringe exchange programme in the 1980s, at an early stage of the HIV/AIDS pandemic. As with many other developed countries, it also provides methadone programmes to reduce both health and social harm from drug use. Most recently, New Zealand has been innovative with a new law involving a pre-market approval scheme with testing requirements and retail restrictions for psychoactive substances that are considered to be “low-risk”. But perhaps New Zealand can do more to manage illicit drugs as a health problem rather than a legal problem, as in Portugal for example. It could also watch developments in US states (Washington State and Colorado) where cannabis sales will be regulated and possibly taxed. This may allow for more quality control of the cannabis sold, and help minimise links between drugs and crime.

Image: There is evidence that methadone programmes are cost-effective interventions

someone drinking methadone

From a health economics perspective, there is evidence from an international review that needle-syringe exchange programmes are cost-effective. In Canada, a supervised injection facility has been reported to be cost saving. There is also evidence from a systematic review that both buprenorphine maintenance therapy and methadone maintenance therapy are cost-effective for the management of opioid-dependent individuals.

In summary, this international work, alongside the recent New Zealand work, should encourage responses by governments and health workers to do more to prevent and treat the high health burden from mental and substance use disorders – it would appear to be a cost effective area to achieve health gains. In particular, they should take the potentially cost-saving steps first, such as raising alcohol tax.

Nick Wilson, University of Otago, Wellington

Public Health Expert Briefing (ISSN 2816-1203)

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