MECHANISMS OF ANTIDEPRESSANT EFFECTS OF BRIGHT LIGHTS

这些研究的主要目的是探索 明亮的光线对冬季抑郁症患者有抗抑郁作用 季节性情感障碍（SAD）。很难排除 安慰剂效应，因为很难设计一个适当的安慰剂 控制有几个问题与使用昏暗的光，最 通常使用的安慰剂，主要是患者通常期望更大 受益于明亮的光线。为了避免这个问题，我们开发了一个 独特的“环境”安慰剂。 患者将在五周平行组设计中接受测试，其中三个 组，早晨光，晚上光和安慰剂。这样我们就能 比较早晨光线和晚上光线的抗抑郁效果， 早晨光照与安慰剂，以及晚上光照与安慰剂。 我们还将评估抗抑郁药 明亮光线的机制是由于昼夜节律的变化。半年 三组中的每一组中的SAD受试者将具有他们的昼夜节律。 连续五周测量体温。年龄和性别 匹配的法线将用作控制。 我们还将研究一组有SAD核心症状的受试者， 能量减少，睡眠增加，食欲增加，但谁不 符合重度抑郁症的标准一个类似的样本被称为 亚综合征SAD流行病学研究表明， 温带地区的人就属于这一类。我们将研究他们的 对强光的反应与上面提到的设计相同。 作为探索机制的进一步手段， 各种症状将在两年内绘制图表，以确定 序列，并记录该综合征的季节性。

The main purpose of these studies is to explore the mechanism(s) by which bright light exerts an antidepressant effect in patients with winter seasonal affective disorder (SAD). It has been difficult to rule out a placebo effect because of the difficulty in designing an adequate placebo control. There are several problems with the use of dim light, the most commonly used placebo, primarily that patients usually expect greater benefit from bright light. To avoid this problem we have developed an unique 'environmental' placebo. Patients will be tested in five-week parallel groups design with three groups, morning light, evening light and placebo. Thus we will be able to compare the antidepressant effect of morning light vs. evening light, morning light vs. placebo, and evening light vs. placebo. We will also evaluate the phase-shift theory that the antidepressant mechanism of bright light is due to shifting circadian rhythms. Half of the SAD subjects in each of the three groups will have their circadian rhythm of body temperature continuously measured for the five weeks. Age and sex matched normals will serve as controls. We will also study a group of subjects who have the core symptoms of SAD, decreased energy, increased sleep, and increased appetite, but who do not meet criteria for major depression. A similar sample has been termed subsyndromal SAD. Epidemiological studies suggest that a large group of people in temperate latitudes fall into this category. We will study their response to bright light with the same design mentioned above. As a further means of exploring mechanisms the fall onset and spring offset of the various symptoms will be charted over two years to determine sequence and to document the seasonal nature of the syndrome.