A cross-correlation analysis of the cyclicity of Italian suicide rates and online suicide-related search volumes

Abstract

IntroductionPeople seeking information and news regarding suicide are likely to use the Internet. There is contrasting evidence about the relationship between the cyclicity of suicide-related search volumes and national suicide-rates in different countries.ObjectivesThe objectives were to investigate first the cyclicity of Italian suicides and online suicide-related searches carried out by the Italian population in the same time frame (2008–2012) and analyze the correlation between the two cyclicities.AimsThe study aimed to gain further insights on suicide-related internet use and its relationships to completed suicides.MethodsItalian mortality database provided monthly national data concerning suicides (2008–2012). Google trends provided data of online monthly search-volumes of the term “suicide”; “commit suicide”; “how to commit suicide” in Google search (2008–2014).ResultsSeasonal AR model suits the trend of Italian suicides with a periodic 1-year cycle. No specific cyclicity for Google search volumes for “how to commit suicide” and “to commit suicide” was found (ARIMA [0,1,1] and ARIMA [1,0,1] respectively). Google search time series for “suicide” performed with ARIMA (1,1,1) and the cross correlation analysis showed that it lags national suicides of three months (ρ = 0.482, P-value < 0.001).ConclusionsOnline searches for suicide-related terms in Italy are more linked to factors other than suicidality such as personal interest and bereavement. To our knowledge, no previous study reported a lag of three months between online searches for “suicide” and national suicides. This may shed further light on the grieving process being of help in organizing effective supportive strategies for the survivors.Disclosure of interestThe authors have not supplied their declaration of competing interest.