Does the growth rate of total amount in cash salaries relate to a transition in the suicide rate?

Abstract

IN JAPAN, THERE were fewer than 25 000 suicides in 1996 and 1997 but more than 30 000 in 1998, a rising trend that has continued. There is evidence that the rapid increase of suicides in recent years in Japan is strongly influenced by economic factors, and that suicide and unemployment are related.1 We previously reported a correlation between the increase of suicides and the change in the ratio of job offers.2 In another report, we showed that stock prices may be associated with suicide among men.3 It is important to clarify the specific economic factors relevant to suicide if we are to lower suicide rates. Therefore, in this study we examined annual suicide rates4 by vital statistics and annual growth rates of total amount in cash salary5 from 1995 to 2009 in Japan, and we assessed the correlation between these factors during that period using single regression analysis in an excel (Microsoft, Japanese, made in Singapore) spreadsheet. During the study period, the annual suicide rates (/100 000 population) ranged from 17.2 to 25.5 overall, from 23.4 to 38.0 among men, and from 11.3 to 14.7 among women. The growth rates of total amount in cash salary during this time ranged from −4.8 to 2.0 (%). The correlation coefficient between suicide rates and the growth rates of total amount in cash salary was r = −0.624 overall, r = −0.627 among men, and r = −0.531 among women. The growth rate of total amount in cash salary was clearly related to the overall suicide rate (R2 = 0.3897, F = 8.300, P = 0.013, and y = −0.9302x + 22.631) and among both men (R2 = 0.3933, F = 8.427, P = 0.012, and y = −1.6267x + 32.811) and women (R2 = 0.2825, F = 5.118, P = 0.041, and y = −0.2663x + 12.909). Given these results, we feel it is helpful to grasp the trends of the growth rate of total amount in cash salaries when attempting to institute suicide-prevention measures, and these trends may be related to the changes in suicide rates among both men and women. A study also reported that socioeconomic variables on suicide are great in Japan.6 Psychiatry professionals should be made aware of this information, as should anyone working in the field of suicide prevention.