Faculty of Veterinary Science, University of Veterinary Science, István u. 2, 1078 Budapest, Hungary.
Demographic Research Institute of the Hungarian Central Statistical Office, Buday László u. 1-3, 1204 Budapest, Hungary.
Prog Neuropsychopharmacol Biol Psychiatry. 2017 Feb 6;73:41-48. doi: 10.1016/j.pnpbp.2016.10.003. Epub 2016 Oct 21.
Several environmental factors with periodic changes in intensity during the calendar year have been put forward to explain the increase in suicide frequency during spring and summer. In the current study we investigated the effect of averaged daily sunshine duration of periods with different lengths and 'lags' (i.e. the number of days between the last day of the period for which the averaged sunshine duration was calculated and the day of suicide) on suicide risk. We obtained data on daily numbers of suicide cases and daily sunshine duration in Hungary from 1979 to 2013. In order to remove the seasonal components from the two time series (i.e. numbers of suicide and sunshine hours) we used the differencing method. Pearson correlations (n=22,950) were calculated to reveal associations between sunshine duration and suicide risk. The final sample consisted of 122,116 suicide cases. Regarding the entire investigated period, after differencing, sunshine duration and number of suicides on the same days showed a distinctly weak, but highly significant positive correlation in the total sample (r=0.067; p=1.17*10). Positive significant correlations (p˂0.0001) between suicide risk on the index day and averaged sunshine duration in the previous days (up to 11days) were also found in the total sample. Our results from a large sample strongly support the hypothesis that sunshine has a prompt, but very weak increasing effect on the risk of suicide (especially violent cases among males). The main limitation is that possible confounding factors were not controlled for.
已经提出了几个在日历年期间强度周期性变化的环境因素来解释春季和夏季自杀频率增加的原因。在目前的研究中，我们调查了不同长度和“滞后”（即计算平均日照时间的时间段的最后一天与自杀日期之间的天数）的平均日日照时间对自杀风险的影响。我们从 1979 年到 2013 年在匈牙利获得了每日自杀案件数和每日日照时间的数据。为了从两个时间序列（即自杀和日照小时数）中去除季节性成分，我们使用了差分法。计算了 Pearson 相关系数（n=22950），以揭示日照时间与自杀风险之间的关联。最终样本包括 122116 例自杀案件。关于整个调查期间，在差分之后，在总样本中，同一天的日照时间和自杀人数显示出明显微弱但高度显著的正相关（r=0.067；p=1.17*10）。在总样本中，还发现指数日自杀风险与前几天（最多 11 天）的平均日照时间之间存在正显著相关（p<0.0001）。我们从大样本中得出的结果强烈支持日照对自杀风险（尤其是男性中的暴力自杀）具有即时但非常微弱的增加作用的假设。主要限制是没有控制可能的混杂因素。
