Bolton Derek, Eley Thalia C, O'Connor Thomas G, Perrin Sean, Rabe-Hesketh Sophia, Rijsdijk Frühling, Smith Patrick
Institute of Psychiatry, Kings College London, UK.
Psychol Med. 2006 Mar;36(3):335-44. doi: 10.1017/S0033291705006537. Epub 2005 Nov 17.
Prevalence of childhood anxiety disorders at specific ages and genetic etiological influences on anxiety disorders in young children have been little studied. The present study reports prevalence estimates in a community sample of 6-year-old twins, and patterns of genetic and environmental influences on these early-onset anxiety disorders.
Using a two-phase design 4,662 twin-pairs were sampled and 854 pairs were assessed in the second phase by maternal-informant diagnostic interview using DSM-IV criteria.
The most common conditions were separation anxiety disorder (SAD) [2.8%, 95% confidence interval (CI) 2.1-3.8, for current disorder] and specific phobia (10.8%, 95% CI 8.4-13.6, for current disorder). Behavioral genetic modeling was feasible for these two conditions, applied to two phenotypes: symptom syndrome (regardless of impairment) and the narrower one of diagnostic status (symptom syndrome with associated impairment). The heritability estimate for SAD diagnostic status was high, 73%, with remaining variance attributed to non-shared environment. The heritability estimates for specific phobia were also high, 80% for the symptom syndrome and 60% for diagnostic status, with remaining variance attributed in both cases to non-shared environment.
Compared with previous epidemiological surveys of children and adolescents in wide age-bands, the current estimates suggest that rates of anxiety disorders assessed in young childhood are generally at least as high and perhaps higher compared with those found in older children. The heritability estimates suggest that the genetic effects on these early-onset anxiety disorders are substantial and more significant than environmental effects, whether shared or non-shared.
儿童焦虑症在特定年龄段的患病率以及遗传病因对幼儿焦虑症的影响鲜有研究。本研究报告了一个6岁双胞胎社区样本中的患病率估计值，以及遗传和环境对这些早发性焦虑症的影响模式。
采用两阶段设计，对4662对双胞胎进行抽样，在第二阶段通过母亲提供信息的诊断访谈，依据《精神疾病诊断与统计手册》第四版标准对854对双胞胎进行评估。
最常见的病症是分离焦虑症（SAD）[当前病症的患病率为2.8%，95%置信区间（CI）为2.1 - 3.8]和特定恐惧症（当前病症的患病率为10.8%，95% CI为8.4 - 13.6）。行为遗传学建模对于这两种病症是可行的，应用于两种表型：症状综合征（无论是否有损害）和较狭义的诊断状态（伴有相关损害的症状综合征）。SAD诊断状态的遗传度估计值很高，为73%，其余变异归因于非共享环境。特定恐惧症的遗传度估计值也很高，症状综合征的遗传度为80%，诊断状态的遗传度为60%，在这两种情况下，其余变异均归因于非共享环境。
与之前对广泛年龄范围的儿童和青少年进行的流行病学调查相比，当前的估计表明，幼儿期评估的焦虑症患病率通常至少与年龄较大儿童的患病率一样高，甚至可能更高。遗传度估计表明，遗传因素对这些早发性焦虑症的影响很大，且比环境因素（无论是共享环境还是非共享环境）的影响更显著。
