This study aimed to explore the gender-based seasonal patterns of suicide in Japan between 2005 and 2012. With data from Japanese official reports, we carried out Prais–Winsten regression and Wilcoxon signed-rank test analysis with Stata 12.0 and SPSS 14.0. The suicide number was significantly higher in March, April, May, June, July, and October for both genders. The suicide number in men was markedly higher than that in women in every month. The suicide number in 2010 was lower than that in 2009 for men, while that in 2011 was higher than that in 2010 for women. The findings displayed that the nationwide television and publicity intervention campaigns might have positive effects on decreasing suicide of men while women suffered a post-earthquake increase. In terms of interventions, we should not only square up the seasonal patterns but also the gender differences in vulnerability.
KevanSM. Perspectives on season of suicide: a review. Soc Sci Med. 1980;14:369-378.
2.
Ajdacic-GrossVBoppMRingMGutzwillerFRosslerW. Seasonality in suicide—a review and search of new concepts for explaining the heterogeneous phenomena. Soc Sci Med. 2010;71657-666.
3.
ChristodoulouCDouzenisAPapadopoulosFC. Suicide and seasonality. Acta Psychiatr Scand. 2012;125:127-146.
4.
LeeHCLinHCTsaiSYLiCYChenCCHuangCC. Suicide rates and the association with climate: a population-based study. J Affect Disord. 2006;92:221-226.
5.
RihmerZRutzWPihlgrenHPestalityP. Decreasing tendency of seasonality in suicide may indicate lowering rate of depressive suicides in the population. Psychiatry Res. 1998;81:233-240.
6.
NaderIWPietschnigJNiederkrotenthalerTKapustaNDSonneckGVoracekM. Suicide seasonality: complex demodulation as a novel approach in epidemiologic analysis. PLoS One. 2011;6:e17413.
7.
WooJMOkusagaOPostolacheTT. Seasonality of suicidal behavior. Int J Environ Res Public Health. 2012;9:531-547.
8.
De VrieseSRChristopheABMaesM. In humans, the seasonal variation in poly-unsaturated fatty acids is related to the seasonal variation in violent suicide and serotonergic markers of violent suicide. Prostaglandins Leukot Essent Fatty Acids. 2004;71:3-18.
9.
MilićCKocićSRadovanovićS. Climate variations—risk factor of committing suicide. Med Pregl [in Serbian]. 2011;64:202-205.
10.
Ajdacic-GrossVLauberCSansossioR. Seasonal associations between weather conditions and suicide—evidence against a classic hypothesis. Am J Epidemiol. 2007;165:561-569.
11.
BauerMGlennTGrofP. Relationship among latitude, climate, season and self-reported mood in bipolar disorder. J Affect Disord. 2009;116:152-157.
12.
RuuhelaRHiltunenLVenäläinenAPirinenPPartonenT. Climate impact on suicide rates in Finland from 1971 to 2003. Int J Biometeorol. 2009;53:167-175.
13.
ReutforsJOsbyUEkbomANordströmPJokinenJPapadopoulosFC. Seasonality of suicide in Sweden: relationship with psychiatric disorder. J Affect Disord. 2009;119:59-65.
14.
ChouFHWuHCChouP. Epidemiologic psychiatric studies on post-disaster impact among Chi-Chi earthquake survivors in Yu-Chi, Taiwan. Psychiatry Clin Neurosci. 2007;61:370-378.
15.
KrugEGKresnowMJPeddicordJP. Retraction: suicide after natural disasters. N Engl J Med. 1999;340:148-149.
16.
SatoT. Seasonality of suicides. Br J Psychiatry. 2001;178:183.
17.
MotohashiY. Suicide in Japan. Lancet. 2012;379:1282-1283.
18.
MearesRMendelsohnFAMilgrom-FriedmanJ. A sex difference in the seasonal variation of suicide rate: a single cycle for men, two cycles for women. Br J Psychiatry. 1981;138:321-325.
19.
NäyhäS. The bi-seasonal incidence of some suicides. Experience from Finland by marital status, 1961-1976. Acta Psychiatr Scand. 1983;67:32-42.
MiccioloRZimmermann-TansellaCWilliamsPTansellaM. Seasonal variation in suicide: is there a sex difference?Psychol Med. 1989;19:199-203.
22.
HoTPChaoAYipP. Seasonal variation in suicides re-examined: no sex difference in Hong Kong and Taiwan. Acta Psychiatr Scand. 1997;95:26-31.
23.
YipPSChaoAChiuCW. Seasonal variation in suicides: diminished or vanished. Experience from England and Wales, 1982-1996. Br J Psychiatry. 2000;177:366-369.
24.
BandoDHScrivaniHMorettinPATengCT. Seasonality of suicide in the city of Sao Paulo, Brazil, 1979-2003. Rev Bras Psiquiatr. 2009;31:101-105.
NiederkrotenthalerTVoracekMHerberthA. Role of media reports in completed and prevented suicide: Werther v. Papageno effects. Br J Psychiatry. 2010;197:234-243.
27.
SisaskMVärnikA. Media roles in suicide prevention: a systematic review. Int J Environ Res Public Health. 2012;9:123-138.
28.
TsaiJF. The media and suicide: evidence-based on population data over 9 years in Taiwan. Suicide Life Threat Behav. 2010;40:81-86.
29.
NishioAAkazawaKShibuyaF. Influence on the suicide rate two years after a devastating disaster: a report from the 1995 Great Hanshin-Awaji Earthquake. Psychiatry Clin Neurosci. 2009;63:247-250.
30.
HyodoKNakamuraKOyamaM. Long-term suicide mortality rates decrease in men and increase in women after the Niigata-Chuetsu earthquake in Japan. Tohoku J Exp Med. 2010;220:149-155.
31.
FushimiMSaitoSShimizuT. Prevalence of depressive symptoms and related factors in Japanese employees as measured by the Center for Epidemiologic Studies Depression Scale (CES-D). Community Ment Health J. 2013;49:236-242.
32.
PretiAMiottoP. Seasonality in suicides: the influence of suicide method, gender and age on suicide distribution in Italy. Psychiatry Res. 1998;81:219-231.
33.
Blasco-FontecillaHPerez-RodriguezMMGarcia-NietoR. Worldwide impact of economic cycles on suicide trends over 3 decades: differences according to level of development. A mixed effect model study. BMJ Open. 2012;2(3):e000785.
34.
McCurryJ. Japan to rethink suicide-prevention policies. Lancet. 2008;371:2071.
