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

Abstract

IntroductionSuicide is a complex and multifactorial phenomenon with growing importance to public health. An increase in its occurrence has been observed in Mexico over the past 10 years. The present article analyzes the secular trend in suicide at the national level between the years 2000 and 2013.Materials and MethodsAll suicides during the study period (n = 64,298, of which 82.11% were men) were characterized using a spectral decomposition of the time series and a wavelet analysis to evaluate the effect of seasonal changes, type of area (urban versus rural) and sex.ResultsA seasonal pattern was observed with statistically significant cycles every 12 months, where peaks were identified in May but only for men in urban zones as of the year 2007. In addition, specific days of the year were found to have a higher frequency of suicides, which coincided with holidays (New Year, Mother’s Day, Mexican Independence Day and Christmas).ConclusionA wavelet analysis can be used to decompose complex time series. To the best of our knowledge, this is the first application of this technique to the study of suicides in developing countries. This analysis enabled identifying a seasonal pattern among urban men in Mexico. The identification of seasonal patterns can help to create primary prevention strategies, increase the dissemination of crisis intervention strategies and promote mental health. These strategies could be emphasized during specific periods of the year and directed towards profiles with a higher risk.

Chris Cornell, the Black Hole Sun, and the Seasonality of Suicide

“…Goodwin and Jamison [7] reviewed 61 studies in the northern hemisphere and found a striking May peak in suicides and a less common, smaller bimodal October peak. Since the review of Goodwin and Jamison [7], there have been dozens of additional studies that have replicated consistent late spring peaks in suicide in nearly all of the largest datasets, including in the northern hemisphere (in those studies that reported both a monthly peak and a total n for suicides), the USA (May; n = 649,843, the present study), Japan (April; n = 501,950 [29]), Sweden (May; n = 161,182 [30]), Italy (May; n = 141,180 [31]), Finland (May; n = 96,159 [30]), England (January; n = 92,909 [32]), Austria (May; n = 67,741 [33]), Mexico (May; n = 64,298 [34]), Spain (July; n = 42,905 [35]), Denmark (May; n = 37,987 [36]), Switzerland (May/June; n = 37,518 [37]), Norway (May; n = 20,156 [38]), China (May; n = 14,450 [39]), and Ireland (April; n = 7,899 [40]). In the southern hemisphere, reciprocal spring peaks have been found in Australia (November; n = 57,936 [41]), South Africa (October; n = 16,389 [42]), and São Paulo, Brazil (November; n = 6,916 [43]).…”

“…Related to the economic hypothesis, a number of studies have examined rural versus urban differences in the seasonality of suicide, and individuals living in rural environments have exhibited greater spring peaks in suicide as compared to individuals living in urban environments. This rural increase has been found in France [6], Hungary [48], New Zealand [49], Sweden [49], and Austria [50], but not in Mexico [34]. The possibility that differences in sunlight and artificial light exposure might account for these urban-rural differences has not previously been considered [51, 52].…”

Demographic and Clinical Characteristics of Completed Suicides in Mexico City 2014–2015

“…In Mexico, suicide rates have been increasing over the past 40 years, affecting more men than women ( 2 ). The suicide rate for men increased from 5.95 to 8.50 (per 100,000 inhabitants) from 2000 to 2015, and from 1.06 to 2.00 for women ( 3 , 4 ). Mexico City, one of the largest urban areas in the world, has one of the lowest suicide rates in the country: the mean standardized suicide rate was 4.1/100,000 for 2015 and 4.8/100,000 for 2014, being 6.8 for males and 1.7 for females in 2015 and 7.9 for males and 2.1 for females in 2014 ( 4 , 5 ).…”

Homicides during the Barranquilla Carnival, Colombia: A 10 Year Time-Series Analysis

“…Other crimes committed on those days have also been reported [20], and these holidays have therefore been considered a risk factor for overall mortality [9], and particularly for deaths from cardiac causes [22,23]. Nevertheless, Mother's Day has only been associated with suicides in Mexico [24]. In the case of Barranquilla, this increase in homicides seems to exist but is relatively minor, which suggests that this effect is mitigated by the nature of the celebration itself, as well as by cultural particularities and the city's security policies.…”