A Study on the Action Mechanisms of Bright Light in Seasonal Affective Disorder

（1）临床研究：在1周的停药期后，对6名住院患者和1名患有季节性情感障碍的门诊患者进行了为期30天的三步光疗法，其中涉及暴露于亮-暗-亮或暗-亮-暗的光。采用汉密尔顿抑郁量表SAD版（HAMSAD）评定抑郁症的临床严重程度。在治疗前，患者完成了关于他们对这种疗法的期望的问卷调查，并进行了Maudsley人格调查。明亮的光线与HAMSAD评分的显着改善相关，而昏暗的光线则没有影响。治疗前患者对强光治疗的期望程度在强光治疗有效组和无效组之间无差异。Maudsley人格调查显示，这两组在任何项目上都没有差异。结果表明，光疗的临床效果可能是基于光的特定效应。（2）动物实验：采用锂和丙咪嗪慢性注射，测定大鼠体温节律和活动节律。锂而不是丙咪嗪延长生物节律的周期。这两种药物都改变了节律的顶点相。

(1)Clinical Study : Following a 1-week drug-free period, a three step light therapy was applied to six inpatients and one outpatient with seasonal affective disorder for a total of 30 days which involved exposure to either bright-dim-bright light or dim-bright-dim light. The irradiation occurred between 6 : 00 AM and 8 : 00 AM.The clinical severity of depression was evaluated using the Hamilton Rating Scale for Depression, SAD version (HAMSAD). Prior to treatment, the patients completed questionnaires concerning their expectations for this therapy, and the Maudsley Personality Inventory was administered.Bright light was associated with significant improvement in HAMSAD scores, whereas dim light had no effect. The degree of patient's expectation for phototherapy before treatment was not different between the effective group and the ineffective group in bright light therapy. The Maudsley Personality Inventory showed no differences between these two groups in any items. The results suggest that the clinical effects of phototherapy may be based on a specific effect of light.(2)Animal Study : Lithium and imipramine were chronically injected into rats, and rhythms of temperature and activity were measured. Lithium but not imipramine lengthened the period of biological rhythms. Both drugs changed the acrophase of rhythms.