• politics
• suicide

The study of ecological influences on suicide, over and above individual level risk factors, is the example par excellence of the social epidemiological approach.¹ In this issue of the journal, Page et al present a fascinating ecological study of the association between suicide rates in New South Wales during the 20th century and various ecological variables, including whether the governing political party was conservative or social democratic.² Consistent with the political disposition of public health researchers (our unstated “observer bias”), suicide rates were indeed higher during periods of conservative government. Apart from confirming our ideological prejudice, such a finding has support from a theoretical perspective. It is not too long a bow to draw to make the connection of conservative government with a greater degree of individualism and retrenchment of the state from the provision of universal public policy, and in turn an increase in “anomie” proposed by Durkheim as a societal cause of suicide.¹ Moreover, we would expect such conditions to result in a reduction in the social cohesion that has been proposed as a determinant of the health status.^3,4 In the United Kingdom, social fragmentation at a small area level has been associated with suicide and cirrhotic liver death independently of deprivation—the same was not true for other causes of death.⁵

Is there a causal association between suicide rates and the political leanings of government? Possibly, but we have several concerns about easily drawing this conclusion. Firstly, the relation observed by Page et al was not statistically significant in the time series analysis—although the direction of the association was the same as the Poisson regression. Secondly, policies are not implemented the day after election night. If government policy causally influences suicide rates one would expect both a time lag and a more fuzzy pattern because of the continuation or only incremental dismantling of the previous government’s conservative/social democratic policies. One would only expect to see an on/off response in suicide rates (Page et al’s “step function”) if the underlying causal mechanism was a pervasive expectation of changes in social attitudes after a change of government. Thirdly, and perhaps most importantly, it is not possible to rule out a spurious or confounded association. For example, the “mood of the nation” and other characteristics of a society may result both in changing suicide rates and changing political preference, thereby inducing a correlation between political affiliation of the government and suicide rates that is not based on causality. Although Page et al controlled for GDP, it is more difficult to assemble data on more sociological confounders. Finally, the analyses of Page et al were confined to New South Wales. One would hope there are similar data for the six other states and territories of Australia to attempt a larger and confirmatory study.

If the association is causal, how can this knowledge be used to support a reduction in suicide rates, which is a stated health goal of several countries? Ecological studies such as this make a contribution to our understanding of the aetiology of suicide. They direct us to consider the context within which important individual level risk factors such as mental illness and substance misuse operate. The typical public health approach demands that the people most likely to be affected be identified. Public health interventions then focus on modifiable risk factors, and, for suicide, individual level factors (such as the presence of mental illness) have recently been considered as the only modifiable risk factors of any note. However, it is questionable whether there could ever be provision of sufficient personal health services to treat the vast societal burden of common problems such as depression and substance misuse, which have strong associations with suicide at the individual level. Findings such as that of Page et al signal a need to consider social level interventions in addition to the targeted individual level interventions (such as treatment of mental illnesses, and psychosocial interventions for children and young people) that governments are already struggling to provide in sufficient quantity.