Young M A, Meaden P M, Fogg L F, Cherin E A, Eastman C I
Institute of Psychology, Illinois Institute of Technology, Chicago 60616-3793, USA.
J Abnorm Psychol. 1997 Nov;106(4):554-62. doi: 10.1037//0021-843x.106.4.554.
The regular fall-winter onset of seasonal affective disorder is believed to be related to seasonal changes in the environment. However, the high correlation among various environmental variables has made it difficult to distinguish which ones may play a causal role. Photoperiod should explain variations in onset risk across both latitude and day of the year because it varies as a function of only these 2 factors. In Study 1, the authors found this to be the case using data from 5 locations. Environmental factors that vary from year to year should explain variations in onset risk across both time of year and actual year. In Study 2, the authors examined data from 7 years at 1 location and failed to find evidence of this effect for daily hours of sunshine, mean daily temperature, and total daily radiation. Findings support photoperiod as being related to the onset of seasonal affective disorder.
季节性情感障碍通常在秋冬季节发作，这被认为与环境的季节性变化有关。然而，各种环境变量之间的高度相关性使得难以区分哪些变量可能起因果作用。光周期应该可以解释纬度和一年中的日期之间发病风险的变化，因为它仅作为这两个因素的函数而变化。在研究1中，作者使用来自5个地点的数据发现情况确实如此。每年变化的环境因素应该可以解释一年中的时间和实际年份之间发病风险的变化。在研究2中，作者检查了一个地点7年的数据，未发现日照时长、日平均温度和日总辐射量对这种效应的影响证据。研究结果支持光周期与季节性情感障碍的发作有关。
