Souêtre E, Salvati E, Belugou J L, Douillet P, Braccini T, Darcourt G
Clinique de psychiatrie et de psychologie médicale, Hôpital Pasteur, Nice, France.
J Affect Disord. 1987 Nov-Dec;13(3):215-25. doi: 10.1016/0165-0327(87)90040-1.
The monthly rates of completed suicides in France from 1978 until 1982 were analyzed. The seasonal variations of environmental (daylight and sunlight durations, mean temperature, geomagnetism), sociological (unemployment, deaths of all causes, birth and conception rates), and biological (melatonin, cortisol and serotonin circannual rhythms) factors were compared to the seasonal patterns of suicides. A clear seasonal variation (with peaks in May and September) in suicidal behavior was detected. These patterns tended to differ as a function of age (bimodal in young, unimodal in old people). The component analysis clearly pointed out that seasonal patterns of suicides may be considered as the sum of two components, unimodal and bimodal. Almost similar covariations were found between the main seasonal (unimodal) component of suicides and environmental (daylight duration and mean monthly temperature) or sociological factors whereas the secondary component was more correlated to variations in environmental factors and, to some extent, to biological parameters.
对1978年至1982年法国每月的自杀既遂率进行了分析。将环境因素（日照时长、阳光照射时长、平均温度、地磁）、社会学因素（失业率、各种原因导致的死亡、出生率和受孕率）以及生物学因素（褪黑素、皮质醇和血清素的年节律）的季节性变化与自杀的季节性模式进行了比较。检测到自杀行为存在明显的季节性变化（5月和9月出现峰值）。这些模式往往因年龄而异（年轻人呈双峰模式，老年人呈单峰模式）。成分分析清楚地指出，自杀的季节性模式可被视为两个成分的总和，即单峰和双峰。在自杀的主要季节性（单峰）成分与环境因素（日照时长和月平均温度）或社会学因素之间发现了几乎相似的协变关系，而次要成分则与环境因素的变化以及在一定程度上与生物学参数的相关性更强。
