Translational Research Informatics Center, Kobe, Japan.
Psychiatry Clin Neurosci. 2014 Jun;68(6):404-9. doi: 10.1111/pcn.12149. Epub 2014 Feb 26.
Some previous studies have shown a positive relation between geomagnetic disturbances and an increased incidence of suicide. If such a relation exists, stronger geomagnetic fields may affect the number of suicides, because stronger geomagnetic fields generally cause larger geomagnetic field disturbances. Therefore, we here investigated the relation between local geomagnetic field magnetic flux density and the standardized morbidity ratios (SMR) for suicide by each prefecture in Japan.
Monthly suicide data for each prefecture in the period January 1999 to December 2008 was obtained, and it was found that a total of 216 171 male individuals and 85 154 female individuals committed suicide during this period. A multiple linear regression analysis was carried out with a backward elimination procedure. The SMR for suicide by each prefecture was taken as the response variable and the explanatory variables were each prefecture's local geomagnetic field magnetic flux density (nT), north latitude (°), monthly mean unemployment rate (%), monthly mean air pressure (hPa), monthly mean air temperature (°C), monthly mean humidity (%), and monthly total day length (hours). Analyses were carried out separately for each sex.
In the multiple linear regression analysis for male subjects, the local geomagnetic field magnetic flux density (nT), monthly mean unemployment rate (%), and monthly mean humidity (%) were associated with the incidence of suicide, but in the multiple linear regression analysis of female subjects, only north latitude was associated with that.
In this study, we generated a hypothesis that stronger geomagnetic fields affect the number of cases of male suicide.
一些先前的研究表明，地磁扰动与自杀发生率增加之间存在正相关关系。如果这种关系存在，更强的地磁场可能会影响自杀人数，因为更强的地磁场通常会导致更大的地磁场扰动。因此，我们在这里调查了日本每个县的局部地磁场磁通密度与自杀标准化发病比（SMR）之间的关系。
获取了 1999 年 1 月至 2008 年 12 月期间每个县的每月自杀数据，在此期间共有 216171 名男性和 85154 名女性自杀。采用向后消除程序进行多元线性回归分析。每个县的自杀 SMR 作为因变量，解释变量为每个县的局部地磁场磁通密度（nT）、北纬（°）、月平均失业率（%）、月平均气压（hPa）、月平均气温（°C）、月平均湿度（%）和月总日照时间（小时）。分别对男性和女性进行了分析。
在男性受试者的多元线性回归分析中，地磁场磁通密度（nT）、月平均失业率（%）和月平均湿度（%）与自杀发生率相关，但在女性受试者的多元线性回归分析中，只有纬度与自杀发生率相关。
在这项研究中，我们提出了一个假设，即更强的地磁场会影响男性自杀病例的数量。
