Hickie I, Kirk K, Martin N
School of Psychiatry, University of New South Wales, Sydney, Australia.
Psychol Med. 1999 Mar;29(2):259-68. doi: 10.1017/s0033291798007934.
Prolonged fatigue syndromes have been proposed as prevalent and disabling forms of distress that occur independently of conventional notions of anxiety and depression.
To investigate the genetic and environmental antecedents of common forms of psychological and somatic distress, we measured fatigue, anxiety, depression and psychological distress in 1004 normal adult twin pairs (533 monozygotic (MZ), 471 dizygotic (DZ)) over 50 years of age.
Familial aggregation of psychological distress, anxiety and fatigue appeared to be due largely to additive genetic factors (MZ:DZ ratios of 2.12-2.69). The phenotypic correlations between the psychological measures (distress, anxiety and depression) were moderate (0.67-0.79) and higher than that between fatigue and psychological distress (0.38). Multivariate genetic modelling revealed a common genetic factor contributing to the development of all the observed phenotypes (though most strongly for the psychological forms), a second independent genetic factor also influenced anxiety and depression and a third independent genetic factor made a major contribution to fatigue alone. In total, 44% (95% CI 25-60%) of the genetic variance for fatigue was not shared by the other forms of distress. Similarly, the environmental factor determining psychological distress made negligible contributions to fatigue, which was underpinned largely by its own independent environmental factor.
This study supports the aetiological independence of prolonged fatigue and, therefore, argues strongly for its inclusion in classification systems in psychiatry.
长期疲劳综合征被认为是一种普遍且使人丧失能力的痛苦形式，其发生独立于焦虑和抑郁的传统概念。
为了研究常见心理和躯体痛苦形式的遗传和环境因素，我们对1004对年龄超过50岁的正常成年双胞胎（533对同卵双胞胎（MZ），471对异卵双胞胎（DZ））测量了疲劳、焦虑、抑郁和心理痛苦程度。
心理痛苦、焦虑和疲劳的家族聚集现象似乎主要归因于加性遗传因素（MZ与DZ的比率为2.12 - 2.69）。心理测量指标（痛苦、焦虑和抑郁）之间的表型相关性中等（0.67 - 0.79），高于疲劳与心理痛苦之间的相关性（0.38）。多变量遗传模型显示，存在一个共同的遗传因素促成所有观察到的表型的发展（尽管对心理形式的影响最为强烈），第二个独立的遗传因素也影响焦虑和抑郁，第三个独立的遗传因素仅对疲劳有主要影响。总体而言，疲劳的遗传变异中有44%（95%置信区间25 - 60%）未被其他痛苦形式所共享。同样，决定心理痛苦的环境因素对疲劳的影响可忽略不计，疲劳主要由其自身独立的环境因素所支撑。
本研究支持长期疲劳在病因学上的独立性，因此强烈主张将其纳入精神病学分类系统。
