How can one explain changes in the monthly pattern of suicide?

Abstract

International audienceThe monthly pattern of suicides has remained a puzzle ever since it was discovered in the second half of the 19th century. In this paper we intend to “explain” not the pattern itself but rather its changes across countries and in the course of time.First, we show that the fairly common idea according to which this pattern is decaying in “modern” societies is not altogether true. For instance, around 2000, in well urbanized countries like South Korea or Spain this pattern was still as strong as it was in France (and other European countries) in the late 19th century.The method that we use in order to make some progress in our understanding is the time-honored Cartesian approach of breaking up the problem under consideration “into as many parts as might be necessary to solve it”. More specifically, we try two separations of monthly suicides into simpler components: (i) according to suicide methods and (ii) according to age-groups. These separations rely on the introduction of what we call “elementary monthly profiles”.The first separation points out the key-role of hanging and drowning. The second shows the crucial role of the 15–20 and 65+65+ age-groups.Then, we present a number of cases in which age-group decomposition provides adequate predictions. It turns out that the cases in which the predictions do not work are newly urbanized countries. The discrepancies may be due to a memory effect which induces a time-lag extending over one or two generations.Finally, in the light of the new results presented in the present paper, we re-examine the theory proposed by Emile Durkheim

Calls due to suicidal behaviour made to the prehospital, emergency department in Málaga: characteristics and associated factors

“…Cabe pensar que en este aspecto hay implicados diversos factores de tipo geográfico, climático, cultural y personal (biológicos y psicológi-cos), que operan interactivamente. En este estudio, las demandas por conducta suicida se dieron más significativamente en agosto y diciembre, en tanto que la mayoría de las publicaciones suelen hablar de la primavera o inicio del verano y apenas en diciembre 6,29,30 . También la conducta suicida se dio más frecuentemente por la tarde, en comparación con las demandas físicas y psiquiá-tricas.…”

Seasonality of suicide: a multi-country multi-community observational study

“…Abundant research dating back to the 19th century demonstrates seasonal suicide patterns, with an increase in spring and a decrease in winter (Durkheim, 1897 ; Maes et al ., 1993 ; Chew and McCleary, 1995 ; Ajdacic-Gross et al ., 2010 ; Christodoulou et al ., 2012 ; Woo et al ., 2012 ; Roehner, 2015 ; Dixon and Kalkstein, 2018 ; Yang et al ., 2019 ). While the pattern of seasonal suicides has been confirmed in many countries, the mechanisms remain unclear.…”

The Mexican Cycle of Suicide: A National Analysis of Seasonality, 2000-2013

“…This relationship between suicides and the effects of the physical external environment has been recognized in documents dating back to the 19 th century [ 7 ], including seasonality, which refers to the fact that suicides have a monthly pattern which tends to repeat yearly [ 8 ]. The seasonality of suicide has been studied based on two broad perspectives, biological and sociological.…”

“…Studying suicide from a sociological perspective, Durkheim (1897) [ 11 ] proposed an opposing theory that increased social activity during spring and summer creates more social stress, and this could lead to suicidal behavior when unable to psychologically cope with the frustration caused by failed social interactions, especially for people with depression [ 9 , 12 , 13 ]. More recent studies of suicides have shown seasonal patterns in different regions and countries, such as the review by Roehner of data from France, Ireland, South Korea and Switzerland [ 8 ]. A study by Petridou, et al .…”